Bump linux-raw-sys to version 0.3.8 to allow to build on longaarch64

[pedrolucasp]

Hello! I'm packing agg to Alpine Linux, and while doing so, the loongarch64 build failed. After digging into it a bit, the linux-raw-sys package was patched a couple of months ago, so I've updated it to a more compatible-version.

See the issue for reference: sunfishcode/linux-raw-sys#34 (comment)

Hit me up if there are any questions or any other paths I should take in order to fix it.

[ku1ik]

Hi @pedrolucasp — thanks a lot for digging into this and sending the patch, and apologies for the long delay in getting back to you!

I tried to resolve the conflict via GitHub's web UI and it ended up producing an invalid Cargo.lock (a [[package]] header got dropped), so the merge state is broken on this branch. But more importantly, I took a look at current main and linux-raw-sys is no longer in the lockfile at all — the transitive dependency that pulled in the old version has since been bumped, so the original loongarch64 build issue is most likely already resolved upstream.

Given that, I'm going to close this PR rather than try to salvage the merge. Could you give a fresh build against current main a try on loongarch64? If it still fails, please open a new issue (or PR) and I'll prioritize it. Either way, really appreciate you packaging agg for Alpine — let me know if anything else comes up there.