Revert "Add "extendWorker" extension point"

This reverts commit bd47559.

packages/core/rpc/BaseRpcDriver.ts

@@ -59,18 +59,11 @@ class LazyWorker {
 
   constructor(public driver: BaseRpcDriver) {}
 
-  async getWorker(pluginManager?: PluginManager) {
+  async getWorker() {
     if (!this.workerP) {
-      if (!pluginManager) {
-        throw new Error("Can't make new worker without plugin manager")
-      }
       this.workerP = this.driver
         .makeWorker()
-        .then(unextendedWorker => {
-          const worker = pluginManager.evaluateExtensionPoint(
-            'Core-extendWorker',
-            unextendedWorker,
-          ) as typeof unextendedWorker
+        .then(worker => {
           watchWorker(worker, this.driver.maxPingTime, this.driver.name).catch(
             error => {
               if (worker) {
@@ -184,10 +177,7 @@ export default abstract class BaseRpcDriver {
     return this.workerPool
   }
 
-  async getWorker(
-    sessionId: string,
-    pluginManager?: PluginManager,
-  ): Promise<WorkerHandle> {
+  async getWorker(sessionId: string): Promise<WorkerHandle> {
     const workers = this.getWorkerPool()
     let workerNumber = this.workerAssignments.get(sessionId)
     if (workerNumber === undefined) {
@@ -197,7 +187,7 @@ export default abstract class BaseRpcDriver {
       workerNumber = workerAssignment
     }
 
-    return workers[workerNumber].getWorker(pluginManager)
+    return workers[workerNumber].getWorker()
   }
 
   async call(
@@ -211,7 +201,7 @@ export default abstract class BaseRpcDriver {
       throw new TypeError('sessionId is required')
     }
     let done = false
-    const worker = await this.getWorker(sessionId, pluginManager)
+    const worker = await this.getWorker(sessionId)
     const rpcMethod = pluginManager.getRpcMethodType(functionName)
     const serializedArgs = await rpcMethod.serializeArguments(args, this.name)
     const filteredAndSerializedArgs = this.filterArgs(serializedArgs, sessionId)