br: skip update follower handle region if no need to scan regions

[Leavrth]

What problem does this PR solve?

Issue Number: ref #58651

Problem Summary:
Some scenarios do not require scanning regions and it is best not to open domain.

What changed and how does it work?

skip opening domain and update follower_handle_region configuration.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

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]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[tiprow]

Hi @Leavrth. Thanks for your PR.

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[ti-chi-bot]

@Leavrth: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
idc-jenkins-ci-tidb/check_dev_2	ad33da7	link	true	/test check-dev2
idc-jenkins-ci-tidb/build	ad33da7	link	true	/test build
pull-mysql-client-test	ad33da7	link	true	/test pull-mysql-client-test
pull-integration-ddl-test	ad33da7	link	true	/test pull-integration-ddl-test
idc-jenkins-ci-tidb/unit-test	ad33da7	link	true	/test unit-test
pull-br-integration-test	ad33da7	link	true	/test pull-br-integration-test
pull-integration-e2e-test	ad33da7	link	true	/test pull-integration-e2e-test
idc-jenkins-ci-tidb/mysql-test	ad33da7	link	true	/test mysql-test
idc-jenkins-ci-tidb/check_dev	ad33da7	link	true	/test check-dev

Full PR test history. Your PR dashboard.

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