Add "Setup Python" action to github-hosted runners

Author: ChrisDenton

.github/workflows/ci.yml

@@ -154,6 +154,12 @@ jobs:
 
       - name: checkout submodules
         run: src/ci/scripts/checkout-submodules.sh
+      
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+        if: runner.environment == 'github-hosted'
 
       - name: install MinGW
         run: src/ci/scripts/install-mingw.sh