After upgrading the system from RHEL7 to RHEL8, yum update fails with an error - Status code: 404

Issue

• yum update command fails with below error after the upgrade from RHEL7 to RHEL8:

  $ yum update
  Updating Subscription Management repositories.
  Red Hat Enterprise Linux 8 for x86_64 - BaseOS (RPMs) 12 kB/s | 4.1 kB 00:00
  Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs) 19 kB/s | 4.5 kB 00:00
  Red Hat Enterprise Linux 7 Server - Extras (RPMs) 15 kB/s | 3.4 kB 00:00
  Red Hat Enterprise Linux 7 Server (RPMs) 5.5 B/s | 10 B 00:01
  Errors during downloading metadata for repository 'rhel-7-server-rpms':
    - Status code: 404 for https://cdn.redhat.com/content/dist/rhel/server/7/8.6/x86_64/os/repodata/repomd.xml 
  Error: Failed to download metadata for repo 'rhel-7-server-rpms': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried