sessiontxn/isolation: fix goleak for TestPessimisticRCTxnContextProviderRCCheckForPrepareExecute

[tiancaiamao]

What problem does this PR solve?

Issue Number: close #36212

Problem Summary:

What is changed and how it works?

Even session.ResultSetToStringSlice(ctx, tk.Session(), rs) return error, the rs should be closed.
Otherwise the will be resource (goroutine) leak.

Check List

Tests

• Unit test

go test -v -run TestPessimisticRCTxnContextProviderRCCheckForPrepareExecute

--- PASS: TestPessimisticRCTxnContextProviderRCCheckForPrepareExecute (0.11s)
PASS
goleak: Errors on successful test run: found unexpected goroutines:
[Goroutine 321 in state select, with github.com/pingcap/tidb/store/copr.(*copIteratorWorker).sendToRespCh on top of the stack:
goroutine 321 [select]:
github.com/pingcap/tidb/store/copr.(*copIteratorWorker).sendToRespCh(0xc00561dc70?, 0x43dfd78?, 0xc0053a0180?, 0x14?)
	/home/genius/project/src/github.com/pingcap/tidb/store/copr/coprocessor.go:542 +0xad
github.com/pingcap/tidb/store/copr.(*copIteratorWorker).run(0xc00561dc70, {0x43dfd78, 0xc0053a0180})
	/home/genius/project/src/github.com/pingcap/tidb/store/copr/coprocessor.go:409 +0xe5
created by github.com/pingcap/tidb/store/copr.(*copIterator).open
	/home/genius/project/src/github.com/pingcap/tidb/store/copr/coprocessor.go:437 +0x78

 Goroutine 450 in state semacquire, with sync.runtime_Semacquire on top of the stack:
goroutine 450 [semacquire]:
sync.runtime_Semacquire(0xc000c3d750?)
	/home/genius/project/go/src/runtime/sema.go:56 +0x25
sync.(*WaitGroup).Wait(0xc0052aef00?)
	/home/genius/project/go/src/sync/waitgroup.go:136 +0x52
github.com/pingcap/tidb/store/copr.(*copIteratorTaskSender).run(0xc004b9ce40)
	/home/genius/project/src/github.com/pingcap/tidb/store/copr/coprocessor.go:477 +0xb3
created by github.com/pingcap/tidb/store/copr.(*copIterator).open
	/home/genius/project/src/github.com/pingcap/tidb/store/copr/coprocessor.go:454 +0x385
]
exit status 1
FAIL	github.com/pingcap/tidb/sessiontxn/isolation	0.585s

• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• Defined2014
• hawkingrei

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[hawkingrei]

/merge

[ti-chi-bot]

@hawkingrei: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

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[hawkingrei]

/merge

[ti-chi-bot]

@hawkingrei: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

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[hawkingrei]

/lgtm

[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/9d45edb35aecca1c17172745b3558b203d7cb8d1

[tiancaiamao]

/merge

[ti-chi-bot]

@tiancaiamao: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[tiancaiamao]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: bd2f740

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! [1] CI still failing after this pr merged.
These failed integration tests don't seem to be introduced by the current PR.

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/tics-test	🔴 failed 1, success 0, total 1	1 min 14 sec	Existing failure
idc-jenkins-ci/integration-cdc-test	🟢 all 36 tests passed	26 min	Existing passed
idc-jenkins-ci-tidb/integration-common-test	🟢 all 11 tests passed	24 min	Existing passed
idc-jenkins-ci-tidb/common-test	🟢 all 12 tests passed	13 min	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	5 min 51 sec	Existing passed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	5 min 22 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	5 min 1 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	3 min 22 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	3 min 2 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed