chore: remove joining emitter (#15588)

Author: pavelfeldman

packages/playwright-core/src/client/channelOwner.ts

@@ -25,9 +25,8 @@ import { zones } from '../utils/zones';
 import type { ClientInstrumentation } from './clientInstrumentation';
 import type { Connection } from './connection';
 import type { Logger } from './types';
-import { JoiningEventEmitter } from './joiningEventEmitter';
 
-export abstract class ChannelOwner<T extends channels.Channel = channels.Channel> extends JoiningEventEmitter {
+export abstract class ChannelOwner<T extends channels.Channel = channels.Channel> extends EventEmitter {
   readonly _connection: Connection;
   private _parent: ChannelOwner | undefined;
   private _objects = new Map<string, ChannelOwner>();