tidb-server: handle the help manually (#24073)

[ti-srebot]

cherry-pick #24073 to release-5.0
You can switch your code base to this Pull Request by using git-extras:

# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/24074

After apply modifications, you can push your change to this PR via:

git push [email protected]:ti-srebot/tidb.git pr/24074:release-5.0-cd25915b51f8

---

What problem does this PR solve?

Issue Number: close #24046

Problem Summary: Check flag: exit 0 when -h or -help invoked but undefined. The newer go does not have this problem. But we can still solve it by manually triggering the usage.

Check List

Tests

• Unit test
• Integration test

Release note

• Set the return value to 0 if --help is passed to cli, for golang below version 1.15

[ti-srebot]

/run-all-tests

[ti-srebot]

@xhebox you're already a collaborator in bot's repo.

[AilinKid]

/LGTM

[AilinKid]

/lgtm

[xiongjiwei]

/lgtm

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AilinKid
• xiongjiwei

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by writing /lgtm in a comment.
Reviewer can cancel approval by writing /lgtm cancel in a comment.

[xhebox]

/merge

[ti-chi-bot]

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

Commit hash: 70a5b22

[xhebox]

/merge

[ti-chi-bot]

@ti-srebot: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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.