(maint) Disable Single Git Source test for el-9, replace 'operatingsystemmajrelease' legacy fact

[rileynewton]

This test fails on el-9 since xinetd has been removed on the platform. Added https://perforce.atlassian.net/browse/PE-36632 for future work to address the possibility of using systemd instead here.

[steveax]

Are we should that fact is gonna be there? It's one of the ones removed in puppet 8.

[rileynewton]

Oh I see, did it change to something else?

[steveax]

os.release.major I think is how you'd reference it, see: https://github.com/puppetlabs/classifier/blob/main/src/puppetlabs/classifier/legacy_fact_translation.clj#L104

[rileynewton]

Confirmed that os.release.major is correct with this test running on el-9:

CODEMGMT-92 - C59235 - Single Git Source Using "GIT" Transport Protocol

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) 15:59:53$ facter --json "os.release.major"
  {
    "os.release.major": "9"
  }

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) executed in 0.49 seconds

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) 15:59:53$ facter --json "os.release.major"
  {
    "os.release.major": "9"
  }

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) executed in 0.51 seconds

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) 15:59:54$ facter --json "os.release.major"
  {
    "os.release.major": "9"
  }

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) executed in 0.51 seconds

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) 15:59:54$ facter --json "os.release.major"
  {
    "os.release.major": "9"
  }

sweet-desk.delivery.puppetlabs.net (redhat9-64-1) executed in 0.51 seconds

This version of EL is not supported by this test case!
Begin teardown
End teardown
Warning: tests/git_source/git_source_git.rb skipped in 2.03 seconds

Looks good but will double check the rest of the tests and ensure there aren't any quirks.