ci: fix powershell publishing job

[Benoît Cortier (CBenoit)]

• Create a tarball archive instead of a zip archive for the PowerShell module.

  • It’s unclear to me why, but the PowerShell module we sign and re-archive in the package workflow is corrupted when we try to decompress it in the release workflow.
  • This is something I could verify locally using the 7z command.

• The Publish-Module cmdlet was also failing with a cryptic error:

  Write-Error: Cannot retrieve the dynamic parameters for the cmdlet. Loading repository store failed: Could not find a part of the path '/home/runner/.local/share/PSResourceGet/PSResourceRepository.xml'.

  • I walked around that by switching to the newer Publish-PSResource cmdlet, which is a more modern rewrite of Publish-Module.