Make unit testing multiple working directories concurrent

[addyess]

Applicable spec:

Overview

Running the tests workflow from a matrix fails because the concurrency group key isn't unique and all but one of the tests is cancelled:

Rationale

I'd like to be able to run multiple unit tests in parallel from my repo like this:

name: Tests

on:
  pull_request:

jobs:
  unit-tests:
    strategy:
      matrix:
        charm: ["foo", "bar"]
    uses: canonical/operator-workflows/.github/workflows/test.yaml@main
    secrets: inherit
    with:
      self-hosted-runner:  false
      working-directory:  ./${{ matrix.charm }}/

Workflow Changes

extend the group key to differentiate by working-directory

Checklist

• The contributing guide was applied
• The PR is tagged with appropriate label (urgent, trivial, complex)

[jdkandersson]

Looks like a bunch of caching things failed here during the tests @weiiwang01

[weiiwang01]

Looks like a bunch of caching things failed here during the tests @weiiwang01

@jdkandersson Yes, I think that was caused by this pull request originating from a forked repository. I think I will just force merge this pull request as this is a very minimal change and I can already see the corresponding tests passed.

[jdkandersson]

/canonical/self-hosted-runners/run-workflows 4abff90

[jdkandersson]

For the record, there are a bunch of CI failures linked to access issues due to this being from a fork. We should always carefully consider what to do in these cases. The tests associated with the unit tests have passed which is what is being changed here so merging without all tests passing.