fix unnecessary resolve lock task

[lidezhu]

What did you do?

ticdc/logservice/logpuller/subscription_client.go

Lines 939 to 950 in f221af5

	gcResolveLastRun := func() {
	if len(resolveLastRun) > 1024 {
	copied := make(map[uint64]time.Time)
	now := time.Now()
	for regionID, lastRun := range resolveLastRun {
	if now.Sub(lastRun) < resolveLockMinInterval {
	resolveLastRun[regionID] = lastRun
	}
	}
	resolveLastRun = copied
	}
	}

Inside gcResolveLastRun, resolveLastRun is always set to an empty map, which causes the resolve lock task throttling mechanism to not work as expected.

What did you expect to see?

No response

What did you see instead?

As described above.

Versions of the cluster

Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

(paste TiCDC version here)