Auto merge of #80041 - jyn514:shrink-item, r=GuillaumeGomez

Get rid of `clean::Deprecation`

This brings the size of `item.deprecation` from 56 to 16 bytes. Helps with #79103 and https://github.com/rust-lang/rust/issues/76382, in the same vein as https://github.com/rust-lang/rust/pull/79957.

r? `@GuillaumeGomez`

diff --cc src/librustdoc/clean/mod.rs
Simple merge

diff --cc src/librustdoc/clean/types.rs
Simple merge

diff --cc src/librustdoc/html/render/mod.rs
Simple merge

diff --cc src/librustdoc/json/conversions.rs
Simple merge