`avoid_final_parameters` lint fires when using a `final` modifier in any
parameter list. This is a preparatory lint that helps us migrate to Dart
3.13. All violations from this lint will become compile-time errors in
Dart 3.13 when the primary constructors feature ships.

Fixes: dart-lang/sdk#62590

**Related to breaking changes:** There should be nothing that breaks
from adding this lint. Function types with `final` are already a
compile-time error and any customers overriding a method with a `final`
parameter won't break their code.

```
// Framework code
class C {
  void m(int x) { ... } // Removed var here.
}
```
```
// ...

// User code
class B implements C {
  void m(final int x) { ... } // Will still work.
}
```

This change should be test exempt.

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- [x] I read the [AI contribution guidelines] and understand my
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- [x] I read the [Tree Hygiene] wiki page, which explains my
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- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

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<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[AI contribution guidelines]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md