build: replace deprecated onwarn with onLog

[btea]

https://rolldown.rs/reference/InputOptions.onwarn#onwarn

[sapphi-red]

Would you split this into two PRs?

[btea]

Sure, I will split this into two PRs.

[sapphi-red]

Thanks!

[btea]

The Circular dependency warning message appears to be a legacy issue, but it doesn't seem to exist now. Perhaps we can simply remove onLog. @sapphi-red

[sapphi-red]

Ah, maybe because https://rolldown.rs/reference/InputOptions.checks#circulardependency is disabled by default. If that's the case, we can simply remove it.

[btea]

Yes, local testing confirms this. Setting checks.circularDependency to true does indeed output multiple circular dependency warnings during the build process.