ref(ci): Use a single CI workflow for tests

[gustavovalverde]

Motivation

This is an initial implementation to solve the re-building of our Docker image, which is being built multiple times by our Github Actions, causing elevated costs across multiple services.

Fixes #7816

PR Author Checklist

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• Will the PR name make sense to users?
• Does the PR have a priority label?
• Have you added or updated tests?
• Is the documentation up to date?

For significant changes:

• Is there a summary in the CHANGELOG?
• Can these changes be split into multiple PRs?

If a checkbox isn't relevant to the PR, mark it as done.

Complex Code or Requirements

• This required creating an extra workflow ci-tests.yml with its respectives .patch.yml and .patch-external.yml to initialize the unit tests and integration tests from a single place, effectively using a single Docker image build process.
• This must be admin merged, and all open PRs must be rebased afterwards.

Solution

• Create a Run tests starter workflow
• Convert the Integration Tests on GCP and Docker Unit Tests to callable workflows
• Merge both of the Integration Tests on GCP and Docker Unit Tests patches files into a single patch file for Run tests

Testing

• Tests should run on this PR successfully

Reviewer Checklist

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• Does the PR scope match the ticket?
• Are there enough tests to make sure it works? Do the tests cover the PR motivation?
• Are all the PR blockers dealt with?
  PR blockers can be dealt with in new tickets or PRs.

And check the PR Author checklist is complete.

Follow Up Work

This must be followed by #8374 to effectively reduce our costs.

[upbqdn]

This PR removes workflow patches for unit tests, but it doesn't do so for integration tests. Why is that?

[gustavovalverde]

This PR removes workflow patches for unit tests, but it doesn't do so for integration tests. Why is that?

The changelog is confusing, but I removed the unit tests patches, and renamed and reused the same patch files for integration tests, those are the new ci-tests.patch.yml and ci-tests.patch-external.yml. This was mainly to reduce the diff.

[gustavovalverde]

@upbqdn after merging your last suggestions, this will require re-approval. Thanks!

[gustavovalverde]

@upbqdn Oops! I had to revert one of the suggestions as I had forgotten the reasoning behind it.

The job is called Build images as the specific workflow that's being (./.github/workflows/sub-build-docker-image.yml) called is used for CI, CD and Release images.

Also, changing the job name here would then require 2 merge rules instead of 1:

Now:

• Build CI Docker / Build images and Build CD Docker / Build images (1 rule)
  After:
• Build CI Docker / Build CI image (1 rule)
• Build CD Docker / Build CD image (1 rule)

This would also be a breaking change, requiring other PRs to be updated. I'd prefer to avoid that in this refactor.