common/pool: fix pool abuse

[0xcb9ff9]

Description

by default ants.NewPool exist expiry, if submit job wait too long time defer function never call, like this

dbsc/core/bloombits/matcher.go

Lines 167 to 170 in 96778f1

	session.pend.Add(1)
	gopool.Submit(func() {
	defer session.pend.Done()
	defer close(results)

[DarianShawn]

Thanks for the great job.
The upstream repo makes something terrible, which we need to fix it step by step. Every small step counts. 🙏

Though I have some questions here.

[DarianShawn]

Excellent. 🙌🏻