Rollup merge of #68994 - Keruspe:sanitizers-conflict, r=Mark-Simulacrum

rustbuild: include channel in sanitizers installed name

Allows parallel install of different rust channels.

I'm not sure if the channel is the right thing to use there, but currently both beta and nightly try to install e.g. `/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_rt.asan.a` when before (and in current stable) it used to be `/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_asan-45a4390180e83d28.rlib` which contained a hash, making it unique.
With this patch, `/usr/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc-nightly_rt.asan.a` gets installed