ENH: Specify Python version in CI documentation build (#89)

.github/workflows/doc_build.yaml

@@ -21,6 +21,11 @@ jobs:
       with:
         fetch-depth: 0
 
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.10'
+
     - name: Install dependencies
       run: |
         python -m pip install --upgrade --user pip setuptools coverage