session: fix data race in TestBootstrap

[wshwsh12]

What problem does this PR solve?

Issue Number: close #39682

Problem Summary:

mustExec only open the executor, but not close it. We need close the recordSet by manual.

What is changed and how it works?

Check List

Tests

• Unit test
• 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:

• hawkingrei
• xhebox

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[xhebox]

/merge

[ti-chi-bot]

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

Commit hash: c588797

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! New failing [1] after this pr merged.
These new failed integration tests seem to be caused by the current PR, please try to fix these new failed integration tests, thanks!

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/mybatis-test	🟥 failed 1, success 0, total 1	3 min 59 sec	New failing
idc-jenkins-ci/integration-cdc-test	🔴 failed 1, success 39, total 40	23 min	Existing failure
idc-jenkins-ci-tidb/integration-common-test	🟢 all 17 tests passed	15 min	Existing passed
idc-jenkins-ci-tidb/common-test	🟢 all 11 tests passed	11 min	Existing passed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	8 min 30 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	6 min 50 sec	Existing passed
idc-jenkins-ci-tidb/tics-test	🟢 all 1 tests passed	6 min 38 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	3 min 48 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	3 min 8 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed

[lcwangchao]

/cherry-pick release-6.5

[ti-chi-bot]

@lcwangchao: new pull request created to branch release-6.5: #49695.

In response to this:

/cherry-pick release-6.5

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