ci: Enable tests on macOS (#1769)

Author: Gustl22

.github/workflows/test.yml

@@ -300,13 +300,12 @@ jobs:
           ( cd server; dart run bin/server.dart ) &
           flutter test -d macos integration_test/platform_test.dart --dart-define USE_LOCAL_SERVER=true
           flutter test -d macos integration_test/lib_test.dart --dart-define USE_LOCAL_SERVER=true
-        # TODO: Integration tests on macOS 13 currently time out.
-        #  flutter test -d macos integration_test/app_test.dart --dart-define USE_LOCAL_SERVER=true
+          flutter test -d macos integration_test/app_test.dart --dart-define USE_LOCAL_SERVER=true
 
   macos-14:
     runs-on: macos-14
     timeout-minutes: 30
-    if: false # TODO: Tests on macOS 14 currently fail.
+    if: inputs.enable_macos
     steps:
       - uses: actions/checkout@v4
       - uses: subosito/flutter-action@v2