`validateWithKzgBatchVerifier` could timeout (12s) and once it times out
because `resChan` is unbuffered, the verifier will stuck at following
line at `verifyKzgBatch` as its waiting for someone to grab the result
from `resChan`:
```
for _, verifier := range kzgBatch {
verifier.resChan <- verificationErr
}
```
Fix is to make kzg batch verification non blocking on timeouts by
buffering each request’s buffered size 1
