Fix Run the tests workflow failure by removing brittle host setup steps

[Copilot]

The Run the tests job was failing before test execution due to swap-file creation on the GitHub runner (fallocate ... /swapfile → Text file busy). This PR removes fragile pre-test runner mutations so the job reaches Docker-based test execution reliably.

• Root-cause removal in run-tests job

  • Removed Maximize build disk space step (jlumbroso/free-disk-space@main).
  • Removed Setup Swap step that created/enabled /swapfile.

• Preserved test execution path

  • Kept checkout, GHCR auth, image pull, and unittest execution unchanged.
  • Retained container memory constraints used by the test run.

• Workflow clarity

  • Normalized the remaining test-step comment to match current behavior.

- name: Run tests in Docker
  run: |
    docker pull ${{ needs.get-docker-meta-data.outputs.tags }}
    docker run --rm \
      --memory="6g" \
      --memory-swap="12g" \
      -v ${{ github.workspace }}:/mnt \
      ${{ needs.get-docker-meta-data.outputs.tags }} \
      python3 -m unittest discover /mnt/tests "*_test.py"