flaky test TestInstancePlanCacheConcurrencySysbench

[lybcodes]

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)

The test branch is the master branch, and Go 1.25 is used. （https://do.pingcap.net/jenkins/job/pingcap/job/tidb/job/ghpr_unit_test/46866/）

testkit.go:171: 
        	Error Trace:	pkg/testkit/testkit.go:171
        	            				pkg/testkit/testkit.go:156
        	            				pkg/planner/core/casetest/instanceplancache/concurrency_test.go:85
        	            				src/runtime/asm_amd64.s:1693
        	Error:      	Received unexpected error:
        	            	[executor:1213]Deadlock found when trying to get lock; try restarting transaction
        	            	github.com/pingcap/errors.Trace
        	            		external/com_github_pingcap_errors/juju_adaptor.go:15
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).ExecWithContext
        	            		pkg/testkit/testkit.go:439
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).MustExecWithContext
        	            		pkg/testkit/testkit.go:168
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).MustExec
        	            		pkg/testkit/testkit.go:156
        	            	pkg/planner/core/casetest/instanceplancache/instanceplancache_test.(*worker).run
        	            		pkg/planner/core/casetest/instanceplancache/concurrency_test.go:85
        	            	runtime.goexit
        	            		src/runtime/asm_amd64.s:1693
        	Test:       	TestInstancePlanCacheConcurrencySysbench
        	Messages:   	sql:update normal.sbtest set c='991' where id=88, [], error stack [executor:1213]Deadlock found when trying to get lock; try restarting transaction
        	            	github.com/pingcap/errors.Trace
        	            		external/com_github_pingcap_errors/juju_adaptor.go:15
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).ExecWithContext
        	            		pkg/testkit/testkit.go:439
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).MustExecWithContext
        	            		pkg/testkit/testkit.go:168
        	            	github.com/pingcap/tidb/pkg/testkit.(*TestKit).MustExec
        	            		pkg/testkit/testkit.go:156
        	            	pkg/planner/core/casetest/instanceplancache/instanceplancache_test.(*worker).run
        	            		pkg/planner/core/casetest/instanceplancache/concurrency_test.go:85
        	            	runtime.goexit
        	            		src/runtime/asm_amd64.s:1693

4. What is your TiDB version? (Required)