Rollup merge of #144700 - aDotInTheVoid:macro-rules-for-macro-fools, r=GuillaumeGomez

rustdoc-json: Move `#[macro_export]` from `Other` to it's own  variant

Followup to rust-lang/rust#142936.

cargo-semver-checks [cares about this attribute](https://github.com/obi1kenobi/trustfall-rustdoc-adapter/blob/4a0d1b0ca19b3115bb65d0b6695c388d7f474ac9/src/visibility_tracker.rs#L459-L476), and it wasn't included in the initial PR for structured attributes CC `@obi1kenobi.`

r? `@GuillaumeGomez`

Author: jhpratt