style: remove empty comments (#23404)

PR Close #23404

packages/core/src/change_detection/change_detector_ref.ts

@@ -6,9 +6,6 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-/**
- *
- */
 export abstract class ChangeDetectorRef {
   /**
    * Marks a view and all of its ancestors dirty.

packages/core/src/change_detection/differs/default_iterable_differ.ts

@@ -557,9 +557,6 @@ export class DefaultIterableDiffer<V> implements IterableDiffer<V>, IterableChan
   }
 }
 
-/**
- *
- */
 export class IterableChangeRecord_<V> implements IterableChangeRecord<V> {
   currentIndex: number|null = null;
   previousIndex: number|null = null;

packages/core/src/change_detection/differs/default_keyvalue_differ.ts

@@ -259,10 +259,6 @@ export class DefaultKeyValueDiffer<K, V> implements KeyValueDiffer<K, V>, KeyVal
   }
 }
 
-
-/**
- *
- */
 class KeyValueChangeRecord_<K, V> implements KeyValueChangeRecord<K, V> {
   previousValue: V|null = null;
   currentValue: V|null = null;