Remove obsolete comment (#120265)

* Remove obsolete comment

The method `_stopCursorTimer` no longer exists.

* Add edited comment back in

Addresses these comments:
- flutter/flutter#120265 (comment)
- flutter/flutter#120265 (comment)

---------

Co-authored-by: Kate Lovett <katelovett@google.com>

Author: suragch

packages/flutter/lib/src/widgets/editable_text.dart

@@ -2605,7 +2605,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
       if (_tickersEnabled && _cursorActive) {
         _startCursorBlink();
       } else if (!_tickersEnabled && _cursorTimer != null) {
-        // Cannot use _stopCursorTimer because it would reset _cursorActive.
+        // Cannot use _stopCursorBlink because it would reset _cursorActive.
         _cursorTimer!.cancel();
         _cursorTimer = null;
       }