maybe fix build

Author: BrightDV

.github/workflows/main.yml

@@ -44,7 +44,7 @@ jobs:
       - run: flutter build apk --release
 
       # Upload generated apk to the artifacts.
-      - uses: actions/upload-artifact@v1
+      - uses: actions/upload-artifact@v2
         with:
           name: app-release.apk
           path: build/app/outputs/apk/release/app-release.apk