gh-actions: add tests for packages built with goreleaser

[olifre]

This tests building the packages, and also testing the deb and rpm packages on various versions of Debian and RockyLinux.

It covers:

• goreleaser building everything (releasing suppressed)
• installation of deb and rpm packages on various distros
• spinning up distro containers including systemd
• testing the systemd unit with a simple config file
• basic test of the installed createtoken binary
• basic test of the shoveler-status binary

@djw8605 I realized current tests did not cover the systemd service nor packaging yet, so I added this as a first step before I will later on attack adding support for running as non-root user. So the tests are essentially the preparation to ensure I don't break anything 😉 .

Checking the goreleaser docs, it seems user creation must be done "classically", i.e. via scripts which are embedded in the packages via goreleaser, following distro best practices (sadly, gorelease can not do that by itself).
Hence, having tests covering the packages and the systemd unit in place first seemed important.

[djw8605]

Thanks for the pull request. I think we are quickly approaching enough complexity to warrant creating an RPM the old fashioned way, rather than using goreleaser.

I’ll review this shortly

[olifre]

I’ll review this shortly

Thanks!
I already fixed a few small nits in two follow-up commits, found during development of the packaging code for local user creation (I'm almost there, will PR this sometime later, likely during the weekend).

[olifre]

I'm almost there, will PR this sometime later, likely during the weekend

That was faster than expected, I'm already done 😉. But I'll hold off on a PR for "run as user" (see https://github.com/olifre/xrootd-monitoring-shoveler/tree/run-as-user ) until both #34 and #23 are in, since it (partially) relies on these two changes.

[olifre]

@djw8605 I have force-pushed here, rebasing onto current main, bumping the Go version used in these added tests to match the one used for the existing tests by now, and also incorporating the new default queue path in these tests.
So this is now up-to-date again.

[djw8605]

Hi @olifre, after merging, the tests fail. Is it because we moved the queue directory? The error gets truncated off from the systemctl status output (should increase that).

Tracking in #56