BUG #16307: pgdg11-updates-debuginfo YUM repository missing RHEL releasever directories

The following bug has been logged on the website:

Bug reference:      16307
Logged by:          Abhijit Menon-Sen
Email address:      ams@2ndquadrant.com
PostgreSQL version: 11.7
Operating system:   RHEL
Description:

When I try to enable and use the newly-introduced "pgdg11-updates-debuginfo"
repository entry in /etc/yum.repos.d/pgdg-redhat-all.repo, it doesn't work
on an RHEL7 VM:

https://download.postgresql.org/pub/repos/yum/debug/11/redhat/rhel-7Server-x86_64/repodata/repomd.xml:
[Errno 14] HTTPS Error 404 - Not Found

This is because the RHEL-specific releasever directories like
"rhel-7Server-x86_64" do not exist in the debug repo, whereas they do exist
in the main repository.

I held off on filing the bug in case there was work ongoing, but the
situation has been unchanged for several days now, hence this report.

This problem likely affects other pgdgNN versions too.