too much logs about `[index_merge_reader.go:791] ["worker finish without panic"]`

[xiongjiwei]

Enhancement

[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergePartialIndexWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.066 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergePartialIndexWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergePartialIndexWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergePartialIndexWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergePartialIndexWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:1343] ["worker finish without panic"] [worker=IndexMergeTableScanWorker]
[2023/03/06 03:44:16.610 +00:00] [INFO] [index_merge_reader.go:791] ["worker finish without panic"] [worker=IndexMergeProcessWorker]

[kolbe]

#41633 added this overly-aggressive log message.

[yibin87]

This issue needs to be cherried pick for 6.5