Upgraded flutter sdk version

Author: BrawlerXull

.github/workflows/flutterci.yml

@@ -26,7 +26,7 @@ jobs:
       # Step 3: Setup Flutter with version 3.7.11
       - uses: subosito/flutter-action@v1
         with:
-          flutter-version: '3.16.4'
+          flutter-version: '3.19.6'
 
       # Step 4: Get dependencies using pub get
       - run: flutter pub get