Rollup merge of #76340 - jonas-schievink:rm-dupe, r=Mark-Simulacrum
Rollup merge of #76340 - jonas-schievink:rm-dupe, r=Mark-Simulacrum

Remove unused duplicated `trivial_dropck_outlives`

The copy that is actually in use now lives here:

https://github.com/rust-lang/rust/blob/d2454643e137bde519786ee9e650c455d7ad6f34/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs#L84

aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust