mcs: add timeout when call alloc of api server

[lhy1024]

What problem does this PR solve?

Issue Number: Close #7207

If scheduling server calls alloc in patrolChecker while destroy cluster, but api server has been closed, scheduling server will always stuck and cannot be closed.

What is changed and how does it work?

Check List

Tests

• Unit test

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• HuSharp
• rleungx

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 submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[codecov]

Codecov Report

Merging #7254 (dc749e7) into master (1899f41) will increase coverage by 0.05%.
Report is 3 commits behind head on master.
The diff coverage is 44.26%.

@@            Coverage Diff             @@
##           master    #7254      +/-   ##
==========================================
+ Coverage   74.35%   74.41%   +0.05%     
==========================================
  Files         446      446              
  Lines       48159    48200      +41     
==========================================
+ Hits        35810    35869      +59     
+ Misses       9191     9176      -15     
+ Partials     3158     3155       -3     

Flag	Coverage Δ
unittests	74.41% <44.26%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

[lhy1024]

/merge

[ti-chi-bot]

@lhy1024: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and 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.

If you have any questions about the PR merge process, please refer to pr process.

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.

[ti-chi-bot]

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

Commit hash: dc749e7