Reuse RenderWorker type (vercel#53782)

Found that this type was duplicated. This just reuses the existing definition.

packages/next/src/server/lib/server-ipc/index.ts

@@ -7,6 +7,7 @@ import crypto from 'crypto'
 import isError from '../../../lib/is-error'
 import { genRenderExecArgv } from '../worker-utils'
 import { deserializeErr } from './request-utils'
+import { RenderWorker } from '../router-server'
 
 // we can't use process.send as jest-worker relies on
 // it already and can cause unexpected message errors
@@ -87,7 +88,7 @@ export const createWorker = async (
   isNodeDebugging: boolean | 'brk' | undefined,
   type: 'pages' | 'app',
   nextConfig: NextConfigComplete
-) => {
+): Promise<RenderWorker> => {
   const { initialEnv } = require('@next/env') as typeof import('@next/env')
   const useServerActions = !!nextConfig.experimental.serverActions
   const { Worker } =
@@ -133,13 +134,7 @@ export const createWorker = async (
       'clearModuleContext',
       'propagateServerField',
     ],
-  }) as any as InstanceType<typeof Worker> & {
-    initialize: typeof import('../render-server').initialize
-    deleteCache: typeof import('../render-server').deleteCache
-    deleteAppClientCache: typeof import('../render-server').deleteAppClientCache
-    clearModuleContext: typeof import('../render-server').clearModuleContext
-    propagateServerField: typeof import('../render-server').propagateServerField
-  }
+  }) as any as RenderWorker
 
   worker.getStderr().pipe(process.stderr)
   worker.getStdout().pipe(process.stdout)