add missing RPM-GPG-KEY-EPEL-9

[vchepkov]

Since AlmaLinux 9 is already in metadata.json, I think this doesn't require any additional changes
But, technically, I don't see why this won't work on RHEL9 and Rocky 9, unless testing suites are not ready yet

a side-note - ScientificLinux never released v8

[jhoblitt]

I'm not sure if this is a bug... It seems more like an enhancement. I guess it depends on if we consider epel a defacto core repo or not.

While adding EPEL9 is consistent with EPEL7 and 8 already supported in this module, the EPEL support overlaps with puppet-epel. Do we need to support configuring the EPEL repos in both mods?

[vchepkov]

I, personally, don't use epel module, since functionality is already available through this module and provides more capabilities

[jhoblitt]

I have been using it since the el4 days. It is convenient to include epel in profiles but I'm not wed to it. It seems like there is an opportunity to simplify here.