Fix deprecated class in request.stub (laravel#46787)

* Replace deprecated Illuminate\Contracts\Validation\Rule with
  ValidationRule.`

src/Illuminate/Foundation/Console/stubs/request.stub

@@ -17,7 +17,7 @@ class {{ class }} extends FormRequest
     /**
      * Get the validation rules that apply to the request.
      *
-     * @return array<string, \Illuminate\Contracts\Validation\Rule|array|string>
+     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array|string>
      */
     public function rules(): array
     {