fix(zone.js): Make EventTarget methods optional in zone.js extension API (#35954)

`zone.js` added `removeAllListeners` and `eventListeners` methods in `EventTarget.prototype`, but those methods only exists when user import `zone.js` and also enables `EventTarget` monkey patching.

If user:
1. Does not import `zone.js` and uses `noop` zone when bootstrapping Angular app. OR
2. Disable monkey patching of `EventTarget` patch by defining `__Zone_disable_EventTarget = true`.

Then `removeAllListeners` and `eventListeners`  methods will not be present.

PR Close #35954

packages/zone.js/lib/zone.api.extensions.ts

@@ -17,22 +17,28 @@ interface EventTarget {
    *
    * Remove all event listeners by name for this event target.
    *
+   * This method is optional because it may not be available if you use `noop zone` when
+   * bootstrapping Angular application or disable the `EventTarget` monkey patch by `zone.js`.
+   *
    * If the `eventName` is provided, will remove event listeners of that name.
    * If the `eventName` is not provided, will remove all event listeners associated with
    * `EventTarget`.
    *
    * @param eventName the name of the event, such as `click`. This parameter is optional.
    */
-  removeAllListeners(eventName?: string): void;
+  removeAllListeners?(eventName?: string): void;
   /**
    *
    * Retrieve all event listeners by name.
    *
+   * This method is optional because it may not be available if you use `noop zone` when
+   * bootstrapping Angular application or disable the `EventTarget` monkey patch by `zone.js`.
+   *
    * If the `eventName` is provided, will return an array of event handlers or event listener
    * objects of the given event.
    * If the `eventName` is not provided, will return all listeners.
    *
    * @param eventName the name of the event, such as click. This parameter is optional.
    */
-  eventListeners(eventName?: string): EventListenerOrEventListenerObject[];
+  eventListeners?(eventName?: string): EventListenerOrEventListenerObject[];
 }