install Python 3.10 in dockerless Windows builds

Author: matthewbastien

.github/workflows/swift_package_test.yml

@@ -672,6 +672,11 @@ jobs:
           }
           docker pull $Image
           echo "image=$Image" >> "$env:GITHUB_OUTPUT"
+      - name: "Install Python 3.10"
+        if: ${{ !inputs.enable_windows_docker }}
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.10"
       - name: Install Visual Studio Build Tools
         if: ${{ !inputs.enable_windows_docker }}
         run: . ${{ steps.script_path.outputs.root }}/.github/workflows/scripts/windows/install-vsb.ps1