set explicit python version

.github/workflows/docs-test.yml

@@ -15,7 +15,7 @@ jobs:
       - name: Install python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.x
+          python-version: 3.12.2
       - name: Setup cache
         uses: actions/cache@v2
         with:
@@ -24,4 +24,4 @@ jobs:
       - name: Setup dependencies
         run: pip install -r docs/requirements.txt
       - name: Build docs
-        run: mkdocs build --strict
+        run: mkdocs build --strict