ci: use maintained action to setup rust toolchain

[roeap]

What changes are proposed in this pull request?

The actions-rs/toolchain action is deprecated in favor of actions-rust-lang/setup-rust-toolchain. This PR updates the usages of the respective actions in the github workflows. THe new action already includes an integration with the rust-cache action, so no need to set that up separately anymore.

This also sets up a dependabot configuration for cargo and github-actions which we may or may not choose to keep.

How was this change tested?

no code changes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.38%. Comparing base (5f23fad) to head (721b2ab).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #585   +/-   ##
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  Coverage   84.38%   84.38%           
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  Files          77       77           
  Lines       19224    19226    +2     
  Branches    19224    19226    +2     
=======================================
+ Hits        16222    16224    +2     
  Misses       2200     2200           
  Partials      802      802           

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[zachschuermann]

nice thanks! changes to existing CI LGTM, just a question on adding dependabot and also overall question: it looks like the two most popular rust toolchains in CI are dtolnay/rust-toolchain and actions-rust-lang/setup-rust-toolchain with the latter saying that it was heavily inspired by dtolnay's? I guess this has caching built-in as the main benefit?

[zachschuermann]

oh nice! are we planning on enabling dependabot for the repo?

[roeap]

well - i guess thats up for debate. but since this was literally just copy and paste from somewhere else, it was low cost to spark the discussion by just providing the solution 😆.

From my end, I think the utility may unfortunately be limited as auto-updates for the major dependencies (e.g. arrow) almost never work out of the box - at least in delta-rs. That said, I still landed on "let's add it" to keep the actions fresh and have the occasional rust version bump that works.

[zachschuermann]

yea I think it is helpful insofar as it just automatically opens small PRs to bump versions and we may (probably) have to manually help upgrade but the 'reminder' to upgrade seems useful? curious to hear what others think

[nicklan]

the dependabot-quickstart-guide doesn't recommend setting up manually like this, but rather suggests going into settings and letting github create this file. Wondering if we should just do it that way?

[nicklan]

I'm okay trying this out, but also a bit skeptical of the utility here. As far as I can tell it only runs cargo update. Generally with how we've set up our Cargo.toml this will only do minor updates (i.e. it'll never update arrow 53->54). Maybe that's good, but we need a process to also run cargo outdated and try and stay on top of more major updates as well, so I'm not sure how much time this saves us.

[zachschuermann]

just want to make sure: is the caching working? I see the following errors in test (ubuntu-latest) in the post-run step:

Error: ENOENT: no such file or directory, opendir '/home/runner/work/delta-kernel-rs/delta-kernel-rs/target/tests/target'
Error: Error: ENOENT: no such file or directory, opendir '/home/runner/work/delta-kernel-rs/delta-kernel-rs/target/tests/target'
... Cleaning cargo registry (cache-all-crates: false) ...
... Cleaning cargo/bin ...
... Cleaning cargo git cache ...
... Saving cache ...
/usr/bin/tar --posix -cf cache.tzst --exclude cache.tzst -P -C /home/runner/work/delta-kernel-rs/delta-kernel-rs --files-from manifest.txt --use-compress-program zstdmt
Failed to save: Unable to reserve cache with key v0-rust-test-64e5ee6e-0ce599cb, another job may be creating this cache. More details: Cache already exists. Scope: refs/pull/585/merge, Key: v0-rust-test-64e5ee6e-0ce599cb, Version: 0d[39](https://github.com/delta-io/delta-kernel-rs/actions/runs/12258931755/job/34199879152#step:7:40)aea52349942f5791850f64e514ac9b6831c456410ea5407f320467a8948d

[nicklan]

looks good for the runner changes. not as sure about dependabot :)

[nicklan]

In yaml double quotes allow escapes and other things, so I tend to prefer single quotes unless I need that, as, fewer surprises. Any reason you changed this?

[roeap]

auto-formatting ... maybe i need to make prettier or whoever it was less agressive :).

[nicklan]

Okay sg. Maybe change back before merge, but not a big deal.

[nicklan]

This link doesn't seem to work. it just goes to a generic support page

[nicklan]

the dependabot-quickstart-guide doesn't recommend setting up manually like this, but rather suggests going into settings and letting github create this file. Wondering if we should just do it that way?

[nicklan]

I'm okay trying this out, but also a bit skeptical of the utility here. As far as I can tell it only runs cargo update. Generally with how we've set up our Cargo.toml this will only do minor updates (i.e. it'll never update arrow 53->54). Maybe that's good, but we need a process to also run cargo outdated and try and stay on top of more major updates as well, so I'm not sure how much time this saves us.

[zachschuermann]

LGTM long as all the caching still works :)

[roeap]

actions now show

... Restoring cache ...
Cache hit for: v0-rust-test-Linux-x64-f47faad6-dc67ccb0
Received 209715200 of 500222278 (41.9%), 199.4 MBs/sec
Received 496027974 of 500222278 (99.2%), 235.8 MBs/sec
Received 500222278 of 500222278 (100.0%), 229.7 MBs/sec
Cache Size: ~477 MB (500222278 B)

so i am reasonably confident the caching still works.

[nicklan]

thanks!

[nicklan]

Okay sg. Maybe change back before merge, but not a big deal.