[retrofit_generator] In Generated Files unused_element_parameter is missing in ignore_for_file

[maui87]

Describe the bug
In newer versions of dart the linter warns about unused_element_parameter.
I use swagger parser which use retrofit to generate the client code.
Without adding the flag to the ignore every unused element parameter ends in a warning.
So if there is no side effect, I would propose to add the flag to the ignore_for_file
I hope I'm correct, that this is a retrofit issue and not a swagger parser issue

To Reproduce
update to newest dart/flutter version and generate code (can confirm it with swagger parser only right now)