Resolve CWG-43 and CWG-42 by applying tox 4 compatability.

Closes CWG-43 Closes CWG-42

.gitlab-ci.yml

@@ -3,7 +3,7 @@ default:
   before_script:
     - python --version # For debugging
     - python -m pip install --upgrade pip
-    - pip install tox twine
+    - pip install --upgrade tox twine
   cache:
     paths:
       - .cache/pip