ci: use dorny/paths-filter to filter paths when running go-tests

[ghaiszaher]

This is just a proposal / discussion starter

what

Instead of having 2 separate workflow files, one that runs tests based on changed paths and the other runs on other changed files, have only one workflow that makes sure to either run tests or no tests.

why

• The issue with current behavior is when pull requests change go and non-go files, we'll have 2 workflows triggered and both fighting for the concurrency lock, whoever wins executes.
• Using on.*.paths, there is no way to ensure test-required.yml is only run if test.yml is skipped (i.e. always give priority to test.yml)

Examples of when test.yml failed to run while there are changed go files:

PR	test.yml skipped	test-required.yml taking over	Note
#3428	runs/5762924585	runs/5762924587/job/15623661330	Was merged although tests are failing
#2782	runs/5872347855	runs/5872347868/job/15923694053
#3451	runs/5490971081	runs/5490971079/job/14871640586

tests

I tested in ghaiszaher#51

drawbacks

• 2 required checks appear in pull requests, but only one of them passing is enough:
  
  (I still see it better than risking skipping tests when they are actually failing)

alternatives

• Always run tests

references

• Closes fix: Investigate why renovate PRs are not running the full CI #3749
• Related to fix: Failing CI after renovate merge #3748

[jamengual]

@GenPage I defer this one to you since you have done considerable amount of work on the workflows

[nitrocode]

As the original writer of #3123 of the negative tests, as (previously) recommended by github docs, FWIW, I'm completely OK with removing the negative tests which are finicky and tricky to debug. This proposed method of using a separate action to do the path filtering will reduce maintenance and make it easier to troubleshoot the triggered action.

[GenPage]

I think this will be more consistent in the long-run, thank you for proposing this.