Remove warning for named arguments

[leonsenft]

Reproduction:

@Component(
  selector: 'app',
  template: '''
    {{quote(value, character: "'")}}
                   ^^^^^^^^^^^^^^
                   Named arguments not allowed in angular templates [disallowed_expression]
  '''
)
class AppComponent {
  final = "Hello world!";

  String quote(String value, {this.character: '"'}) => value;
}

Support for named arguments was added in version 5.0.0.

[MichaelRFairhurst]

Awesome!

(Also, somehow I missed this!)