Add tests trigger on action release

[SuperKogito]

• Add trigger to launch workflow in urlchecker-test-repo.

• Aims to fix https://github.com/urlstechie/urlchecker-action/issues/43.

• This workflow is based on the following:

  • https://github.community/t5/GitHub-Actions/Github-Action-trigger-on-release-not-working-if-releases-was/td-p/34559
  • https://twitter.com/GeertvdC/status/1183837353493893122
  • https://github.community/t5/GitHub-Actions/Triggering-by-other-repository/m-p/30668

[vsoch]

This shouldn't be necessary if we put the tests here, where they should be :)

[vsoch]

This also isn't logical because it's going to fire testing after a release... we need to test for any PR for urlchecker-action. Here is what you should do.

• Take the tests that you are adding to urlchecker-test-repo and add them alongside the tests we have here, which are already started in main.yml
• those tests are already running on PR, which is what we want
• close both these PRs.

If you ever aren't sure about an issue (e.g., the one you wanted to address here) please ping me on the issue and we can talk about it first! I think the work you did will still be useful for the urlchecker-test-repo, you just need to move the content into a PR over here.