Prevent bots/analyze.dart crashing on circular dependencies (#123802)

Prevent bots/analyze.dart crashing on circular dependencies

Author: DanTup

dev/bots/analyze.dart

@@ -1772,7 +1772,14 @@ Future<void> _checkConsumerDependencies() async {
 
       final List<String> currentDependencies = (currentPackage['dependencies']! as List<Object?>).cast<String>();
       for (final String dependency in currentDependencies) {
-        workset.add(dependencyTree[dependency]!);
+        // Don't add dependencies we've already seen or we will get stuck
+        // forever if there are any circular references.
+        // TODO(dantup): Consider failing gracefully with the names of the
+        //  packages once the cycle between test_api and matcher is resolved.
+        //  https://github.com/dart-lang/test/issues/1979
+        if (!dependencies.contains(dependency)) {
+          workset.add(dependencyTree[dependency]!);
+        }
       }
     }
   }