Update main.yml

Author: lijy91

.github/workflows/main.yml

@@ -17,7 +17,7 @@ jobs:
       - uses: subosito/flutter-action@v2
       - run: |
           sudo apt-get update -y
-          sudo apt-get install -y ninja-build libgtk-3-dev
+          sudo apt-get install -y ninja-build libgtk-3-dev libappindicator3-dev
       - run: flutter config --enable-linux-desktop
       - run: cd example && flutter build linux -v
   build-macos: