Ubuntu – App Engine says "Your runtime version for ruby33 is past End of Support", but it isn't

As written in google documentation here and here

I use the latest runtime of Ruby available in app engine.

My worker.yml starts like that:

runtime: ruby33
env: flex
service: default
entrypoint: bundle exec sidekiq
resources:
  cpu: 2
  memory_gb: 1.6
  disk_size_gb: 10

My Gemfile starts like so:

source 'https://rubygems.org'

ruby "3.3.1"

My Gemfile.lock ends like that:

RUBY VERSION
   ruby 3.3.1p55

BUNDLED WITH
   2.3.26

My Dockerfile starts like that:

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.1
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim as base

My cloudbuild.yaml looks like that

#First I build the image:
  - id: "Build worker"
    name: "gcr.io/cloud-builders/docker"
    script: |
      #!/usr/bin/env bash
      docker build --target worker -t $_IMAGE_URL .

#Then I deploy it:
 - id: "Launch worker"
   name: 'gcr.io/google.com/cloudsdktool/cloud-sdk:alpine'
   script: |
     #!/usr/bin/env bash
     gcloud app deploy worker.yaml --image-url=$_IMAGE_URL --quiet

but when deploying, I get this error:

Step #13 – "Launch worker": ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: Error(s) encountered validating runtime. Your runtime version for ruby33 is past End of Support. Please upgrade to the latest runtime version available..

I have no idea how to fix it. Can you help me?