(MODULES-11807) add EL10 basic support - align EL10 PGSQL 16 default package version

[SugatD]

This PR is created to execute tests for the original PR (#1650)

[jst-cyr]

@SugatD : The original maintainer has updated their code to try to resolve the acceptance issues. Can we update this branch again and retest so we can provide additional feedback?

[SugatD]

@jst-cyr Updated this branch with the maintainer's latest commits from #1650 (EL10 fail() guard in dnfmodule.pp, the EL10→PG16 default in globals.pp, EL10 metadata entries, and the server_instance_spec.rb guard restricted to EL8/9) and re-ran acceptance.

The RHEL-10 acceptance tests now pass — both RedHat-10 and RedHat-10-arm are green, where the run previously failed on server_instance_spec.rb trying to run dnf module enable postgresql:16 on EL10. RedHat-8/9 and the rest of the EL8/EL9 family (CentOS, Oracle, Rocky, Alma) also remain green.

The remaining 4 failures are unrelated to this change:

• CentOS-7 / Scientific-7 / OracleLinux-7 (EOL EL7) — the PostgreSQL service fails to start in the Litmus container (Connection refused on port 5432), which cascades into the dependent examples. Environmental, not a regression from the EL10 work.
• Debian-13 — a new platform unrelated to the EL10 support added here.

So the EL10 acceptance issue flagged earlier is resolved. Ready for additional feedback.

[SugatD]

Closing this PR as the #1650 is merged