Remove Swatinem/rust-cache

[joshua-spacetime]

Description of Changes

Also add v8 and openssl cache restore to dependent jobs.

rust-cache build artifacts can be anywhere between 1GB and 3GB depending on the job. The actions cache itself is only 10GB. And these entries are not long-lived. They're being uploaded constantly for a few reasons:

1. The key is very broad and according to the Swatinem/rust-cache docs, it includes:

   a hash of all Cargo.lock / Cargo.toml files found anywhere in the repository

   Therefore, even changing a crate that a particular job does not build can produce a new cache key.

2. GitHub caches are scoped by branch/ref. A cache written by a PR is generally not reused by master after merge. So essentially the same artifact is inserted into the cache twice, potentially consuming over half of the cache's available space.

We need to revisit caching at some point, but rust-cache is probably not the solution b/c of the above reasons. Ultimately we need to make sure that cache entries have a reasonable shelf-life, which they do not currently.

API and ABI breaking changes

N/A

Expected complexity level and risk

1

Testing

N/A

[bfops]

works for me. I dream of the day we remove openssl entirely, but today is not that day.