Improve BPF SDK dependency caching

[jackcmay]

Problem

BPF dependencies can be expensive to download/untar/clone

Summary of Changes

Improve dependency caching by:

• Avoid copying by downloading directly to the cache
• Reduce untar time by untaring into cache
• Cache cloned repos

Fixes #10369

[jackcmay]

@mvines You mentioned

cloning https://github.com/solana-labs/rust-bpf-sysroot.git: uncached but also anonymous http

Can you elaborate?

[mvines]

I github grants a better rate limit if you believe git clone over ssh instead of http, since it can identify you. But if we're caching the clone then this is probably a moot point

[jackcmay]

@mvines Think we should backport this to 1.1 too?

[mvines]

Sure