Fix setup-rust cache

[Sec-ant]

The current cache settings of the action setup-rust are not working well. We've reached the limit and the caches are not being restored or saved properly. This also slows down the codegen job.

I'll look into it.

[Sec-ant]

Should be fixed by #539.

[Sec-ant]

The synchronize workflow will update Cargo.toml and Cargo.lock when it runs the codegen job (bump the revision of biome). And the cache key is hashed against the Cargo.lock file. That's why every time it runs, it will save the cache with a new cache key. Thus filling up the cache storage rapidly (10 Gb limit)

I'll try disabling caching provided by that action and handling the cache by ourselves.

[ematipico]

Do we need caching at this point?

[Sec-ant]

Do we need caching at this point?

Yes, or rust will build all the dependencies each time we run codegen.

[Sec-ant]

After #552, we now use a single cache key rust-cache to restore and update the rust cache, the cache storage will no longer be filled by different rust caches and we can still speed up our build time with it.

We probably should do the same for the pnpm cache. Because each time when synchronize workflow is exectued, pnpm lockfile is also updated, so its cache is invalidated. So the cache is not being used, and only eating up the storage.

[Sec-ant]

I'm sorry for reopening this again. But the current workaround is not ideal for the following reasons:

1. The cache paths are not properly cleaned before saving, that will result in a bigger and bigger cache file. We should take the clean-up functions in moonrepo/setup-rust for reference
2. The cache saving action cannot be put in a post run step, which prolongs the job duration.
3. The current workaround is not reusable.
4. We need something good enough we can use for all our repos.

To address the above issues, I plan to fork https://github.com/moonrepo/setup-rust and do some experiments.

So I reopen this issue as a reminder.

[ematipico]

CI and caching, two difficult things combined! You're brave @Sec-ant 👏