flutter: Run tests on the CI as well

Invoked under xvfb, as GH doesn't have X11

.github/workflows/flutter-dev.yml

@@ -26,12 +26,16 @@ jobs:
         preset:
           - name: dev-flutter
             isAOT: false
+            args: []
           - name: dev-flutter-asan
             isAOT: false
+            args: ["--asan"]
           - name: dev-flutter-aot
             isAOT: true
+            args: ["--aot"]
           - name: dev-flutter-aot-asan
             isAOT: true
+            args: ["--aot", "--asan"]
 
     steps:
       - name: Checkout sources
@@ -40,7 +44,7 @@ jobs:
       - name: Install dependencies on Ubuntu
         run: |
           sudo apt update -qq
-          sudo apt install libgtk-3-dev libglib2.0-dev ninja-build libspdlog-dev lld -y
+          sudo apt install libgtk-3-dev libglib2.0-dev ninja-build libspdlog-dev lld xvfb -y
 
       - uses: subosito/flutter-action@v2
         with:
@@ -82,3 +86,6 @@ jobs:
         run: |
           cd examples/flutter
           flutter build linux
+
+      - name: Run tests
+        run: xvfb dart run_flutter_tests.dart ${{ join(matrix.preset.args, ' ') }}