Upgrade GitHub Actions, drop remaining Python 3.9 references

.github/workflows/test-pyodide.yml

@@ -12,15 +12,15 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v7
     - name: Set up Python 3.10
-      uses: actions/setup-python@v6
+      uses: actions/setup-python@v7
       with:
         python-version: "3.10"
         cache: 'pip'
         cache-dependency-path: '**/setup.py'
     - name: Cache Playwright browsers
-      uses: actions/cache@v4
+      uses: actions/cache@v6
       with:
         path: ~/.cache/ms-playwright/
         key: ${{ runner.os }}-browsers