Ensure tox failure fails CI job rather than silently passing

Set the test step shell to `bash -eo pipefail` and redirect `tox` stderr into `tee` (changed `tox -q` to `tox -q 2>&1 | tee tox-output.log`). This ensures pipeline failures are detected (pipefail) and that tox's stderr is recorded in `tox-output.log` for improved debugging in the CI workflow.

Author: C-Achard

.github/workflows/testing-ci.yml

@@ -54,8 +54,9 @@ jobs:
             libxcb-cursor0
 
       - name: Run tests (exclude hardware) with coverage via tox
+        shell: bash -eo pipefail {0}
         run: |
-          tox -q | tee tox-output.log
+          tox -q 2>&1 | tee tox-output.log
 
 
       - name: Append Coverage Summary to Job