[inspector] collect old async stack traces 20% faster

src/inspector/v8-debugger.h

Index: src/inspector/v8-debugger.h
diff --git a/src/inspector/v8-debugger.h b/src/inspector/v8-debugger.h
index 02a42cb8fdbddc6a24de8843ae325d686a5a249f..f5e251a9bdd07a32d8b3293da76285d9e8e0b8a2 100644
--- a/src/inspector/v8-debugger.h
+++ b/src/inspector/v8-debugger.h
@@ -200,7 +200,6 @@ class V8Debugger : public v8::debug::DebugDelegate {
   std::vector<std::shared_ptr<AsyncStackTrace>> m_currentAsyncCreation;
 
   void collectOldAsyncStacksIfNeeded();
-  void removeOldAsyncTasks(AsyncTaskToStackTrace& map);
   int m_asyncStacksCount = 0;
   // V8Debugger owns all the async stacks, while most of the other references
   // are weak, which allows to collect some stacks when there are too many.