CI - Bump actions/checkout from v3 -> v4

[bfops]

Description of Changes

All I can say is that this stopped us from getting a cryptic permission denied error when trying to package the CLI for release. I have literally no idea why we got the error, or why this fixes it.

but.. new versions can't be bad, right? ..right?!

May Git have mercy on our souls.

API and ABI breaking changes

No. CI-only change.

Expected complexity level and risk

1

Testing

• [ ] The CLI builds successfully on the release branch with this cherrypicked in.