[FEATURE REQUEST] Generated code 'part of' should be consistent and linting

[freemansoft]

💬 Description

tokens.g.dart and tokens_extra.g.dart declare the part of differently and the 3.0 linter complains about one of them. The lint rules say that they should be the same style. https://pub.dev/packages/flutter_lints

// passes lint
part 'tokens_extra.g.dart';
// generates lint warning
part of tokens;

❓ Link to specification or documentation (if available)

Do you want them to be the same? If so, I can generate a PR.

That is the only warning I have for the example with the 3.0 linter