RPM cannot be signed with V4 signature only in Red Hat Enterprise Linux 8

Issue

• We signed our custom RPM package with RPM V4 signature by following this article: https://access.redhat.com/articles/3359321
• I removed --force-v3-sigs option from gpg command options to sign it with RPM V4 signature.
• Our expectation was that the signed RPM package has the RPM V4 signature only after reading this blog article:
  https://www.redhat.com/en/blog/securing-rpm-signing-keys
• But the result was that it had the two signatures.

# rpm -Kv /root/rpmbuild/RPMS/x86_64/custom-1.0-1.el8.x86_64.rpm
/root/rpmbuild/RPMS/x86_64/custom-1.0-1.el8.x86_64.rpm:
    Header V4 RSA/SHA256 Signature, key ID 47fca7e4: OK   <<=== for Header
    Header SHA256 digest: OK
    Header SHA1 digest: OK
    Payload SHA256 digest: OK
    V4 RSA/SHA256 Signature, key ID 47fca7e4: OK          <<=== for Header + Payload
    MD5 digest: OK

• How can we make a V4 signature only in our RPM package?