unnecessary_setters_getters should allow when one is deprecated

[srawlins]

I have code that looks like this:

class C {
  List<dynamic> _captured;

  List<dynamic> get captured => _captured;

  @Deprecated(
      'captured should be considered final - assigning this field may be '
      'removed as early as Mockito 5.0.0')
  set captured(List<dynamic> captured) => _captured = captured;
}

Both the setter and getter have been flagged by unnecessary_setters_getters, but I think they should be allowed, as one is @Deprecated.

[pq]

I tend to agree.

@bwilkerson?

[bwilkerson]

It wouldn't be inconsistent if deprecated elements were treated like they were already gone. Not sure how often this comes up, but I wouldn't object to it.

See also #58119 for another possible tweak to the rule.