perf(concurrency): cancel remaining goroutines when has error

[eileenaaa]

Description

This PR optimizes goroutine execution in multi-task scenarios:

• Uses errgroup.WithContext to manage multiple goroutines and propagate cancellation signals.
• When any goroutine encounters an error, errgroup automatically cancels the remaining goroutines, allowing them to exit early.
• Reduces unnecessary computation and resource usage when partial failures occur.

This improves system responsiveness and reduces wasted CPU cycles in error cases.

Checklist

• Code compiles correctly and linting passes locally
• For all code changes, an entry added to the CHANGELOG.md file describing and linking to
  this PR
• Tests added for new functionality, or regression tests for bug fixes added as applicable

[ghost]

Can you instead use errGroup to do the same thing?

[eileenaaa]

Can you instead use errGroup to do the same thing?

Yes, that works. I’ve implemented the same logic using an errgroup with context—please review code again.

Also, a quick question: since we’re using egCtx (from errgroup.WithContext(ctx)),
it already inherits all features from the parent ctx, including cancellation and timeouts.
In handleUidPostings, there’s still a check on the parent ctx every 100 iterations (around line 812 in worker/task.go).
Given that, is this check still necessary, or is there a specific reason for keeping it?

[ghost]

If we don't have that check, it could take a long time for a thread to finish as this one thread with no errors could take long when other threads have been cancelled.