chore: Bump flutter-gh-pages

Author: spydon

.github/workflows/gh-pages.yml

@@ -11,6 +11,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: subosito/flutter-action@v2
-      - uses: bluefireteam/flutter-gh-pages@v8
+      - uses: bluefireteam/flutter-gh-pages@v9
         with:
           workingDir: example