ci: rename Flutter SDK setup step in test workflow

Author: nixrajput

.github/workflows/test.yml

@@ -52,7 +52,7 @@ jobs:
         with:
           sdk: ${{ matrix.sdk }}
 
-      - name: Install Flutter SDK
+      - name: Set up Flutter SDK
         uses: subosito/flutter-action@v2
         with:
           channel: stable