docs: fix typo in control_value_accessor.ts (#37057)

This commit updates the `ControlValueAccessor` class description in the `@angular/forms` package to fix a typo.

PR Close #37057

packages/forms/src/directives/control_value_accessor.ts

@@ -80,7 +80,7 @@ export interface ControlValueAccessor {
 
   /**
    * @description
-   * Registers a callback function is called by the forms API on initialization
+   * Registers a callback function that is called by the forms API on initialization
    * to update the form model on blur.
    *
    * When implementing `registerOnTouched` in your own value accessor, save the given