Upgrade Flutter version used in CI

Signed-off-by: Michaël Ohayon <[email protected]>

Author: mikklfr

.github/workflows/dart.yml

@@ -22,7 +22,7 @@ jobs:
     - name: Install Flutter
       uses: subosito/flutter-action@v1
       with:
-        flutter-version: '2.0.3'
+        flutter-version: '3.27.3'
     - name: Install dependencies
       run: flutter pub get
     - name: Run dart analyze