linter: Skip rule message descriptions check on Windows

Change-Id: I11d7e9ec22fc6b2ac707240102d2cabfc6c64f4f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/365986
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Samuel Rawlins <srawlins@google.com>
diff --git a/pkg/linter/test/validate_no_rule_description_references_test.dart b/pkg/linter/test/validate_no_rule_description_references_test.dart
index 063d365..021f4b7 100644
--- a/pkg/linter/test/validate_no_rule_description_references_test.dart
+++ b/pkg/linter/test/validate_no_rule_description_references_test.dart
@@ -9,7 +9,10 @@
 import 'package:test/test.dart';
 
 void main() {
-  group('check for rule message descriptions in tests:', () {
+  group('check for rule message descriptions in tests:',
+      // We just need to validate rule message descriptions in one CI bot.
+      onPlatform: {'windows': Skip('Windows host may not have "grep" tool')},
+      () {
     registerLintRules();
     for (var rule in Analyzer.facade.registeredRules) {
       test(rule.name, () async {