Remove deprecated removeSubscription from the type of NativeEventEmitter (#39115)

Summary:
Removed deprecated function removeSubscription from the type of NativeEventEmitter, so that it lines up with its implementation. This is a fix for https://github.com/facebook/react-native/issues/39111 .

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[General] [Fixed] - Fix a type issue of NativeEventEmitter

Pull Request resolved: https://github.com/facebook/react-native/pull/39115

Test Plan: Not applicable

Reviewed By: NickGerleman

Differential Revision: D48573676

Pulled By: lunaleaps

fbshipit-source-id: e70c951e230e0d236e0bf0a1ba02b450bdc98ac5

packages/react-native/Libraries/EventEmitter/NativeEventEmitter.d.ts

@@ -60,10 +60,4 @@ declare class NativeEventEmitter extends EventEmitter {
    * @param eventType  name of the event whose registered listeners to remove
    */
   removeAllListeners(eventType: string): void;
-
-  /**
-   * Removes a subscription created by the addListener, the EventSubscription#remove()
-   * function actually calls through to this.
-   */
-  removeSubscription(subscription: EmitterSubscription): void;
 }

packages/react-native/types/__typetests__/index.tsx

@@ -1068,7 +1068,6 @@ const sub2 = androidEventEmitter.addListener(
 androidEventEmitter.listenerCount('event'); // $ExpectType number
 sub2.remove();
 androidEventEmitter.removeAllListeners('event');
-androidEventEmitter.removeSubscription(sub1);
 
 // NativeEventEmitter - IOS
 const nativeModule: NativeModule = {
@@ -1081,7 +1080,6 @@ const sub4 = iosEventEmitter.addListener('event', (event: object) => event, {});
 iosEventEmitter.listenerCount('event');
 sub4.remove();
 iosEventEmitter.removeAllListeners('event');
-iosEventEmitter.removeSubscription(sub3);
 
 class CustomEventEmitter extends NativeEventEmitter {}