Rollup merge of #56116 - alexcrichton:tarball-calng, r=kennytm
Rollup merge of #56116 - alexcrichton:tarball-calng, r=kennytm

ci: Download clang/lldb from tarballs

Hopefully will speed up CI slightly!

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