Upgrade a whole lot of GitHum Actions references

.github/workflows/test-pyodide.yml

@@ -12,7 +12,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Python 3.10
       uses: actions/setup-python@v6
       with:
@@ -20,7 +20,7 @@ jobs:
         cache: 'pip'
         cache-dependency-path: '**/pyproject.toml'
     - name: Cache Playwright browsers
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       with:
         path: ~/.cache/ms-playwright/
         key: ${{ runner.os }}-browsers