Add missing mutex lock to NetworkHandler::disable() (facebook#55241)

Summary:

TSIA

Reviewed By: hoxyq

Differential Revision: D90998980

Author: motiz88

packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp

@@ -56,6 +56,7 @@ bool NetworkHandler::disable() {
   }
 
   enabled_.store(false, std::memory_order_release);
+  std::lock_guard<std::mutex> lock(requestBodyMutex_);
   responseBodyBuffer_.clear();
   return true;
 }