huge logs for "event feed receives a region error" and "region worker get a region error" during initial scan

[fubinzh]

What did you do?

1. What did you do?
2. Deploy TiDB cluster with 6 TiKV and 2 CDC
3. Stop GC
4. Run workload for 1 days to generate hube incremetal data for cdc to sync
5. Resume cdc changefeed with start-ts earlier to initial scan for workload events.

What did you expect to see?

1. There should not be too much

What did you see instead?

1. There are too much logs about "event feed receives a region error" and "region worker get a region error", which are introduced by kv-client(cdc): fix the bug that region errors can be lost (#9963) #9977

Versions of the cluster

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

[root@tc-tikv-0 /]# /tikv-server -V
TiKV
Release Version:   7.6.0-alpha
Edition:           Community
Git Commit Hash:   04ab96c248408ef4c71807b527f9cc925ce8fb42
Git Commit Branch: heads/refs/tags/v7.5.0-pr16048-04ab96
UTC Build Time:    2023-11-23 07:55:18
Rust Version:      rustc 1.67.0-nightly (96ddd32c4 2022-11-14)
Enable Features:   pprof-fp jemalloc mem-profiling portable sse test-engine-kv-rocksdb test-engine-raft-raft-engine cloud-aws cloud-gcp cloud-azure openssl-vendored
Profile:           dist_release

TiCDC version (execute cdc version):

[root@tc-ticdc-0 /]# /cdc version
Release Version: v7.5.0
Git Commit Hash: 8c006b38bdc304201d646c35c993156abcc2b845
Git Branch: heads/refs/tags/v7.5.0
UTC Build Time: 2023-11-20 05:31:19
Go Version: go version go1.21.3 linux/amd64
Failpoint Build: false

[fubinzh]

/severity major

[fubinzh]

/label affects-6.5
/label affects-7.1
/label affects-7.5

[hicqu]

Closed by #10268.

[zimulala]

Closed by #10241.