flaky test TestIssue48756

[hawkingrei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

2. What did you expect to see? (Required)

3. What did you see instead (Required)

     result.go:49: 
        	Error Trace:	pkg/testkit/result.go:49
        	            				pkg/executor/test/executor/executor_test.go:3002
        	Error:      	Not equal: 
        	            	expected: "[Warning 1292 Incorrect time value: '120120519090607']\n[Warning 1105 ]\n"
        	            	actual  : "[Warning 1292 Incorrect time value: '1 1:1:1.0000027']\n[Warning 1105 ]\n"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1,2 +1,2 @@
        	            	-[Warning 1292 Incorrect time value: '120120519090607']
        	            	+[Warning 1292 Incorrect time value: '1 1:1:1.0000027']
        	            	 [Warning 1105 ]
        	Test:       	TestIssue48756
        	Messages:   	sql:show warnings, args:[] 

https://tiprow.hawkingrei.com/view/gs/pingcapprow/pr-logs/pull/pingcap_tidb/56194/fast_test_tiprow/1838871558488068096#1:build-log.txt%3A3676

4. What is your TiDB version? (Required)

[zimulala]

It's not very good reproduction (run 500+ times can only be reproduced once). We could consider lowering some of our priorities

[hawkingrei]

https://do.pingcap.net/jenkins/blue/organizations/jenkins/pingcap%2Ftidb%2Frelease-7.5%2Fghpr_unit_test/detail/ghpr_unit_test/2248/tests