Add Python 3.10 Sphinx 4

Author: sciencewhiz

.github/workflows/workflow.yml

@@ -36,6 +36,8 @@ jobs:
             sphinx-version: '4'
           - python-version: '3.9'
             sphinx-version: '4'
+          - python-version: '3.10'
+            sphinx-version: '4'
     name: "Test Extension - Python(${{ matrix.python-version }}), Sphinx(${{ matrix.sphinx-version }})"
     steps:
       - uses: actions/checkout@v4