unrelated_type_equality_checks does not lint enums

[ltOgt]

Describe the issue

The unrelated_type_equality_checks lint does not lint comparing unrelated enums.

To Reproduce

With analysis_options.yaml

linter:
  rules:
    - unrelated_type_equality_checks

And main.dart

enum Enum1 {
  one,
}

enum Enum2 {
  two,
}

class A {}

class B {}

void main(List<String> args) {
  A() == B(); // Equality operator `==` invocation with references of unrelated types. dart(unrelated_type_equality_checks)
  A() != B(); // Equality operator `==` invocation with references of unrelated types. dart(unrelated_type_equality_checks)
  Enum1.one == Enum2.two; // No lint
  Enum1.one != Enum2.two; // No lint
}

Expected behavior

Comparing enums of unrelated types should be linted by the unrelated_type_equality_checks lint.

Additional context

$ dart --version
Dart SDK version: 2.18.6 (stable) (Tue Dec 13 21:15:14 2022 +0000) on "macos_arm64"

[srawlins]

Thanks for filing an issue. Duplicate of #58653.