chore: dummy test for GitHub actions

thermion_dart/test/dummy_tests.dart

@@ -0,0 +1,10 @@
+// just for investigating crashes on GitHub actions
+import 'package:test/test.dart';
+
+void main() async {
+  group("test", () {
+    test("test", () {
+      expect(1, 1);
+    });
+  });
+}