Auto merge of #54271 - petrochenkov:nolegder, r=eddyb,alexcrichton

Unsupport `#[derive(Trait)]` sugar for `#[derive_Trait]` legacy plugin attributes

This is a long deprecated unstable feature that doesn't mesh well with regular resolution/expansion.

How to fix broken code:
- The recommended way is to migrate to stable procedural macros - derives or attributes (https://doc.rust-lang.org/nightly/book/first-edition/procedural-macros.html).
- If that's not possible right now for some reason, you can keep code working with a simple mechanical replacement `#[derive(Legacy)]` -> `#[derive_Legacy]`.

Closes https://github.com/rust-lang/rust/issues/29644

r? @ghost