deps: remove unused c8 and update cross-spawn resolution

[RinZ27]

I removed c8 and its related coverage configurations since we're not really using it anymore. This naturally resolves the security alerts caused by the older cross-spawn version that c8 was pulling in, while also cleaning up some technical debt.

I've also kept the cross-spawn resolution just to be safe in case any other transitive deps are still hitting it, but the primary fix was stripping out the unused dependency as suggested.

[connorjclark]

I'd rather just update whatever dep is pulling this in. I think it's c8, which we don't really use anymore and should just remove.

[RinZ27]

@connorjclark Agreed. If we're not using c8 anymore, dropping it is a much better long-term fix than patching the transitive dep. I'll check the build/test configs and strip it out.

[RinZ27]

@connorjclark Done. I've stripped out c8 and cleaned up the related coverage configurations as we discussed, which I believe is a much cleaner approach. This also naturally resolves the cross-spawn vulnerability. I noticed the Vercel preview build is failing, but after checking my changes, I suspect it might be an environment issue or unrelated to the dependency removal—could you or someone else on the team take a look when you have a moment?

[KrrishSR4]

Reviewed the changes.

Removing the unused c8 dependency makes sense and effectively addresses the cross-spawn vulnerability while reducing technical debt. Keeping the resolution as a safety net also looks reasonable.

LGTM 👍

[RinZ27]

@KrrishSR4 Appreciate the feedback!