BUG #17403: Package postgresql13-13.6-1PGDG.rhel7.x86_64.rpm is not signed

The following bug has been logged on the website:

Bug reference:      17403
Logged by:          Guillermo Jano
Email address:      guillermo.jano@hpecds.com
PostgreSQL version: 13.6
Operating system:   CentOS Linux release 7.9.2009
Description:

When trying to install PostgreSQL 13 from the yum repository for RHEL/CentOS
7.9 we are facing the following error:

    Package postgresql13-13.6-1PGDG.rhel7.x86_64.rpm is not signed

In fact I can see the latest RPM is not signed:

    # rpm -Kv

https://download.postgresql.org/pub/repos/yum/13/redhat/rhel-7.9-x86_64/postgresql13-server-13.6-1PGDG.rhel7.x86_64.rpm


https://download.postgresql.org/pub/repos/yum/13/redhat/rhel-7.9-x86_64/postgresql13-server-13.6-1PGDG.rhel7.x86_64.rpm:
        Header SHA1 digest: OK (0b1add03c2c1be5c7dd9707bbf12e634905529ee)
        MD5 digest: OK (99f61e16d94faa246f0236649f3798b1)

whereas the previous one was:

    # rpm -Kv https://download.postgresql.org/p

ub/repos/yum/13/redhat/rhel-7.9-x86_64/postgresql13-server-13.5-1PGDG.rhel7.x86_64.rpm


https://download.postgresql.org/pub/repos/yum/13/redhat/rhel-7.9-x86_64/postgresql13-server-13.5-1PGDG.rhel7.x86_64.rpm:
        Header V4 DSA/SHA1 Signature, key ID 442df0f8: NOKEY
        Header SHA1 digest: OK (bd7788d6d1c07793107fc442475b98438ba4f5df)
        MD5 digest: OK (a8c3ac6f66522a0cdb4bfc308af6615d)
        V4 DSA/SHA1 Signature, key ID 442df0f8: NOKEY