Rollup merge of #120384 - wackbyte:array-equality-generics, r=Mark-Simulacrum

Use `<T, U>` for array/slice equality `impl`s

Makes the trait implementation documentation for arrays and slices appear more consistent.

[Example](https://doc.rust-lang.org/1.75.0/std/primitive.array.html): mixed `A`, `B`, and `U`.
![List of PartialEq implementations for arrays](https://github.com/wackbyte/rust/assets/29505620/823c010e-ee57-4de1-885b-a1cd6dcaf85f)

This change makes them all `U`.

Author: matthiaskrgr