Rollup merge of #133960 - jdonszelmann:remove-eq-on-attributes, r=notriddle

rustdoc: remove eq for clean::Attributes

This change removes the `PartialEq` and `Eq` implementations from `Attributes`. This implementation was not used, and whether the implementation is useful at all is questionable. I care about removing it, because I'm working #131229. While simplifying the representation of attributes, I intend to remove attr ids from attributes where possible. They're actually rarely useful. This piece of code uses them, but for no real reason, so I think simply removing the implementation makes most sense. Let me know if there are major objections to this.

Author: matthiaskrgr