Rust 1.63 added derive_partial_eq_without_eq to clippy, which gives us a lint that when we derive PartialEq, we should also derive Eq when we can.
Eq requires reflexivity, i.e. a == a. PartialEq is for the case where this is not necessarily true, like for NaN for floats. Since we have reflexivity for these errors, the lint is a true positive and this diff fixes it.