workflow: simplify unit test running in the GH workflow

Run only two jobs in the GH runner for the unittest. The `test_stage.py`
because it takes a very long time and needs to run in parallel and
all the other tests.

This split avoid that we forget to add new unittests to the matrix
as we did before (see e.g. https://github.com/osbuild/osbuild/pull/1731)
and it will also enable the tests in:
- sources/test
- inputs/tests
- mounts/test

to run.

This will reduce the "granularity" of the test output a bit, in the
GH runner we only see two unit test matrix jobs now. However that
should not be too bad because the non-stage tests are really quick
to run.

.github/workflows/test.yml

@@ -7,9 +7,6 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  # setting workers to 1 just to have the same syntax in all test
-  # but to disable parallelism for the majority who have concurrency issues
-  TEST_WORKERS: "-n 1"
   # Share the store between the workers speeds things up further
   OSBUILD_TEST_STORE: /var/tmp/osbuild-test-store
 
@@ -21,26 +18,12 @@ jobs:
       fail-fast: false
       matrix:
         test:
-          - "test.mod"
-          - "test.run.test_boot"
-          - "test.run.test_devices"
-          - "test.run.test_executable"
-          - "test.run.test_mount"
-          - "test.run.test_noop"
-          - "test.run.test_sources"
-          - "test.run.test_stages"
-          - "stages/test"
-          - "tools/test"
+          - parallel
+          - normal
         environment:
           - "py36"    # RH8
           - "py39"    # RH9
           - "py312"   # latest fedora
-        # special keyword "include"
-        include:
-          # this test _can_ run in parallel
-          # Using 4 workers is a bit arbitrary, "auto" is probably too aggressive.
-          - test: "test.run.test_stages"
-            env_TEST_WORKERS: "-n 4"
     steps:
     - name: "Clone Repository"
       uses: actions/checkout@v4
@@ -54,9 +37,16 @@ jobs:
           # it to vfs for the local storage skopeo stage test.
           sed -i 's/overlay/vfs/g' /usr/share/containers/storage.conf  # default system config
           sed -i 's/overlay/vfs/g' /etc/containers/storage.conf || true  # potential overrides
-          TEST_WORKERS="${{ matrix.env_TEST_WORKERS || env.TEST_WORKERS }}" \
+          if [ "${{ matrix.test }}" == "parallel" ]; then
+              # 4 is a bit arbitrary
+              TEST_WORKERS="-n 4"
+              TEST_CATEGORY="test_stages.py"
+          else
+              # test_assemblers.py is run below
+              TEST_CATEGORY="not test_stages.py and not test_assemblers.py"
+          fi
           OSBUILD_TEST_STORE="${{ env.OSBUILD_TEST_STORE }}" \
-          tox -e "${{ matrix.environment }}" -- ${{ matrix.test }}
+          tox -e "${{ matrix.environment }}" -- $TEST_WORKERS -k "$TEST_CATEGORY"
 
   v1_manifests:
     name: "Assembler test (legacy)"
@@ -72,6 +62,5 @@ jobs:
         with:
           image: ghcr.io/osbuild/osbuild-ci:latest-202308241910
           run: |
-            TEST_WORKERS="${{ env.TEST_WORKERS }}" \
             OSBUILD_TEST_STORE="${{ env.OSBUILD_TEST_STORE }}" \
-            tox -e "py36" -- test.run.test_assemblers
+            tox -e "py36" -- ${{ env.TEST_WORKERS }} test.run.test_assemblers