Rollup merge of #50527 - glandium:cleanup, r=sfackler
Rollup merge of #50527 - glandium:cleanup, r=sfackler

Cleanup a `use` in a raw_vec test

`allocator` is deprecated in favor of `alloc`, and `Alloc` is already imported
through `super::*`.

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