src: remove unimplemented method in TracingAgent

PR-URL: https://github.com/nodejs/node/pull/26959
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

src/inspector/tracing_agent.h

@@ -28,8 +28,6 @@ class TracingAgent : public NodeTracing::Backend {
       std::unique_ptr<protocol::Array<String>>* categories) override;
 
  private:
-  void DisconnectTraceClient();
-
   Environment* env_;
   std::shared_ptr<MainThreadHandle> main_thread_;
   tracing::AgentWriterHandle trace_writer_;