Update web deployment workflow

Author: kaboc

.github/workflows/gh_pages.yml

@@ -10,9 +10,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+          flutter-version: 3.16.9
       - name: Update dependencies
         run: flutter pub upgrade
-      - uses: bluefireteam/flutter-gh-pages@v8
+      - uses: bluefireteam/flutter-gh-pages@v9
         with:
           workingDir: example
           baseHref: /flutter_custom_text/