Add .gemini/ to test exemption list (#4815)

See https://github.com/flutter/flutter/pull/172887#issuecomment-3130140772
diff --git a/app_dart/lib/src/request_handlers/github/webhook_subscription.dart b/app_dart/lib/src/request_handlers/github/webhook_subscription.dart
index 230d93e..0b97e56 100644
--- a/app_dart/lib/src/request_handlers/github/webhook_subscription.dart
+++ b/app_dart/lib/src/request_handlers/github/webhook_subscription.dart
@@ -721,6 +721,7 @@
         filename.endsWith('pubspec.yaml') ||
         filename.endsWith('pubspec.yaml.tmpl') ||
         // Exempt categories.
+        filename.contains('.gemini/') ||
         filename.contains('.github/') ||
         filename.endsWith('.md') ||
         // Exempt paths.
diff --git a/app_dart/test/request_handlers/github/webhook_subscription_test.dart b/app_dart/test/request_handlers/github/webhook_subscription_test.dart
index a708fc4..a994185 100644
--- a/app_dart/test/request_handlers/github/webhook_subscription_test.dart
+++ b/app_dart/test/request_handlers/github/webhook_subscription_test.dart
@@ -1541,7 +1541,7 @@
     });
 
     test(
-      'Framework no comment if only CODEOWNERS or TESTOWNERS changed',
+      'Framework no comment if only CODEOWNERS or TESTOWNERS or .gemini/ changed',
       () async {
         const issueNumber = 123;
         tester.message = generateGithubWebhookMessage(
@@ -1554,6 +1554,8 @@
           (_) => Stream<PullRequestFile>.fromIterable(<PullRequestFile>[
             PullRequestFile()..filename = 'CODEOWNERS',
             PullRequestFile()..filename = 'TESTOWNERS',
+            PullRequestFile()..filename = '.gemini/styleguide.md',
+            PullRequestFile()..filename = '.gemini/config.yaml',
           ]),
         );