Xcode build failed after I updated Flutter

The Console is telling me the following:

Failed to build iOS app
Error output from Xcode build:
↳
    ** BUILD FAILED **


Xcode's output:
↳

    Command PhaseScriptExecution failed with a nonzero exit code
    note: Using new build system
    note: Building targets in parallel
    note: Planning build
    note: Constructing build description
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'leveldb-library' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'gRPC-Core' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'gRPC-C++' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'gRPC-C++-gRPCCertificates-Cpp' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'abseil' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'BoringSSL-GRPC' from project 'Pods')
    warning: The iOS Simulator deployment target 'IPHONEOS_DEPLOYMENT_TARGET' is set to 8.0, but the range of supported deployment target versions is 9.0 to 14.4.99. (in target 'Flutter' from project 'Pods')

Could not build the application for the simulator.
Error launching application on iPhone 12.

I am new to programming and don’t know what to do.

When I run flutter build ios –verbose:

[ +380 ms] executing: sysctl hw.optional.arm64
[  +85 ms] Exit code 1 from: sysctl hw.optional.arm64
[   +1 ms] sysctl: unknown oid 'hw.optional.arm64'
[  +24 ms] executing: [/Users/tlobry/Desktop/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[  +56 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] b22742018b3edf16c6cadd7b76d9db5e7f9064b5
[   +3 ms] executing: [/Users/tlobry/Desktop/flutter/] git tag --points-at b22742018b3edf16c6cadd7b76d9db5e7f9064b5
[ +168 ms] Exit code 0 from: git tag --points-at b22742018b3edf16c6cadd7b76d9db5e7f9064b5
[        ] 2.2.0
[  +24 ms] executing: [/Users/tlobry/Desktop/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[  +36 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] origin/beta
[        ] executing: [/Users/tlobry/Desktop/flutter/] git ls-remote --get-url origin
[  +33 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[ +356 ms] executing: [/Users/tlobry/Desktop/flutter/] git rev-parse --abbrev-ref HEAD
[  +37 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[   +1 ms] beta
[  +17 ms] executing: sw_vers -productName
[  +46 ms] Exit code 0 from: sw_vers -productName
[        ] Mac OS X
[        ] executing: sw_vers -productVersion
[  +36 ms] Exit code 0 from: sw_vers -productVersion
[        ] 10.15.7
[        ] executing: sw_vers -buildVersion
[  +37 ms] Exit code 0 from: sw_vers -buildVersion
[        ] 19H114
[ +243 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[  +11 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[ +173 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
[        ] Artifact Instance of 'GradleWrapper' is not required, skipping update.
[        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[  +18 ms] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[        ] Artifact Instance of 'FlutterSdk' is not required, skipping update.
[        ] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'PubDependencies' is not required, skipping update.
[  +68 ms] "flutter ios" took 371ms.
[  +87 ms] Target file "lib/main.dart" not found.
[   +7 ms] 
           #0      FlutterCommand.validateCommand (package:flutter_tools/src/runner/flutter_command.dart:1322:9)
           #1      FlutterCommand.verifyThenRunCommand (package:flutter_tools/src/runner/flutter_command.dart:1148:11)
           <asynchronous suspension>
           #2      FlutterCommand.run.<anonymous closure> (package:flutter_tools/src/runner/flutter_command.dart:1043:27)
           <asynchronous suspension>
           #3      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #4      CommandRunner.runCommand (package:args/command_runner.dart:196:13)
           <asynchronous suspension>
           #5      FlutterCommandRunner.runCommand.<anonymous closure> (package:flutter_tools/src/runner/flutter_command_runner.dart:284:9)
           <asynchronous suspension>
           #6      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #7      FlutterCommandRunner.runCommand (package:flutter_tools/src/runner/flutter_command_runner.dart:232:5)
           <asynchronous suspension>
           #8      run.<anonymous closure>.<anonymous closure> (package:flutter_tools/runner.dart:62:9)
           <asynchronous suspension>
           #9      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #10     main (package:flutter_tools/executable.dart:91:3)
           <asynchronous suspension>
           
           
[ +469 ms] ensureAnalyticsSent: 366ms
[  +10 ms] Running shutdown hooks
[   +1 ms] Shutdown hooks complete
[   +5 ms] exiting with code 1

Btw. Stackoverflow tells me "
It looks like your post is mostly code; please add some more details." but I cannot explain more. Does someone know how to bypass the problem?