Ignore unawaited_futures lint in dev/automated_tests (#182922)

Not adding `await` is expected - see
`dev/automated_tests/flutter_test/test_async_utils_guarded_expectation.txt`
and
`dev/automated_tests/flutter_test/test_async_utils_unguarded_expectation.txt`.

dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart

diff --git a/dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart b/dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart
index 1a80e4f..aea7c0b 100644
--- a/dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart
+++ b/dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart
@@ -25,7 +25,7 @@
   testWidgets('TestAsyncUtils - custom guarded sections', (WidgetTester tester) async {
     await tester.pumpWidget(Container());
     expect(find.byElementType(Container), isNotNull);
-    guardedHelper(tester);
+    guardedHelper(tester); // ignore: unawaited_futures
     expect(find.byElementType(Container), isNull);
     // this should fail
   });

dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart

diff --git a/dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart b/dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart
index 59786f3..9ebe42d 100644
--- a/dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart
+++ b/dev/automated_tests/flutter_test/test_async_utils_unguarded_test.dart
@@ -22,8 +22,8 @@
   testWidgets('TestAsyncUtils - handling unguarded async helper functions', (
     WidgetTester tester,
   ) async {
-    helperFunction(tester);
-    helperFunction(tester);
+    helperFunction(tester); // ignore: unawaited_futures
+    helperFunction(tester); // ignore: unawaited_futures
     // this should fail
   });
 }