test: ensure removeListener event fires for once() listeners

Adds test coverage for the removeListener event being emitted
when a once() listener is automatically removed after execution.
This verifies that streams and other EventEmitters correctly
emit removeListener events when once() wrappers clean up.

PR-URL: #60137
Fixes: #59977
Reviewed-By: Aviv Keller <[email protected]>
Reviewed-By: Chemi Atlow <[email protected]>
Reviewed-By: Rafael Gonzaga <[email protected]>
Reviewed-By: Gürgün Dayıoğlu <[email protected]>

Author: Han5991

lib/events.js

@@ -687,9 +687,10 @@ EventEmitter.prototype.removeListener =
           this._events = { __proto__: null };
         } else {
           delete events[type];
-          if (events.removeListener)
-            this.emit('removeListener', type, list.listener || listener);
         }
+
+        if (events.removeListener !== undefined)
+          this.emit('removeListener', type, list.listener || listener);
       } else if (typeof list !== 'function') {
         let position = -1;
 

test/parallel/test-event-emitter-remove-listeners.js

@@ -168,3 +168,19 @@ function listener2() {}
   ee.removeListener('foo', listener1);
   assert.strictEqual(ee._events.foo, listener2);
 }
+
+{
+  const { Writable } = require('stream');
+  const stream = new Writable({
+    write(chunk, encoding, callback) {
+      callback();
+    }
+  });
+
+  stream.on('removeListener', common.mustCall((eventName, listener) => {
+    assert.strictEqual(eventName, 'finish');
+  }));
+
+  stream.once('finish', common.mustCall());
+  stream.end();
+}