autocomplete: Remove mistaken paragraph in `onSelected` doc (#130190)

Fixes #130187.

Fixes #130187 by removing the mistaken paragraph; see there for details.

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

@@ -244,10 +244,6 @@ class RawAutocomplete<T extends Object> extends StatefulWidget {
 
   /// {@template flutter.widgets.RawAutocomplete.onSelected}
   /// Called when an option is selected by the user.
-  ///
-  /// Any [TextEditingController] listeners will not be called when the user
-  /// selects an option, even though the field will update with the selected
-  /// value, so use this to be informed of selection.
   /// {@endtemplate}
   final AutocompleteOnSelected<T>? onSelected;