Updated files with 'repo_helper'.

Author: repo-helper[bot]

.github/workflows/docs_test_action.yml

@@ -29,7 +29,7 @@ jobs:
               - '!tests/**'
 
       - name: Install and Build 🔧
-        uses: sphinx-toolbox/[email protected]
+        uses: sphinx-toolbox/[email protected]-py39
         if: steps.changes.outputs.code == 'true'
         with:
           pre-build-command: python -m pip install tox