Failed to download metadata for repo 'pgdg-common' on centos 7

when I try to install or update packages on my CentOS Stream 8 than this error occurs

[root@e2e-101-138 ~]# sudo yum update
PostgreSQL common RPMs for RHEL / Rocky 8 - x86_64                                                           613  B/s | 659  B     00:01
PostgreSQL common RPMs for RHEL / Rocky 8 - x86_64                                                           1.6 MB/s | 1.7 kB     00:00
PostgreSQL common RPMs for RHEL / Rocky 8 - x86_64                                                           503  B/s | 659  B     00:01

Error: Failed to download metadata for repo 'pgdg-common': repomd.xml GPG signature verification error: Bad GPG signature

I tried to install docker or just update the packages or libraries on my Centos 7 server.

server details ==>

[root@e2e-101-138 ~]# hostnamectl
   Static hostname: e2e-101-138
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 7bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
           Boot ID: c0xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    Virtualization: kvm
  Operating System: CentOS Stream 8
       CPE OS Name: cpe:/o:centos:centos:8
            Kernel: Linux 4.18.0-529.el8.x86_64
      Architecture: x86-64