fix: openkruise health check npe error

[alswl]

Related to issue https://github.com/argoproj/argo-cd/issues/19545

Checklist:

• [ ] Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes.
• [ ] The title of the PR states what changed and the related issues number (used for the release note).
• [ ] The title of the PR conforms to the Toolchain Guide
• [ ] I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• [ ] I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• [ ] Does this PR require documentation updates?
• [ ] I've updated documentation as required by this PR.
• [ ] I have signed off all my commits as required by DCO
• [ ] I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• [ ] My build is green (troubleshooting builds).
• [ ] My new feature complies with the feature status guidelines.
• [ ] I have added a brief description of why this PR is necessary and/or what this PR solves.
• [ ] Optional. My organization is added to USERS.md.
• [ ] Optional. For bug fixes, I've indicated what older releases this fix should be cherry-picked into (this may or may not happen depending on risk/complexity).

[bunnyshell[bot]]

:x: Preview Environment deleted from Bunnyshell

Available commands (reply to this comment):

• :rocket: /bns:deploy to deploy the environment

[bunnyshell[bot]]

:x: Preview Environment deleted from Bunnyshell

Available commands (reply to this comment):

• :rocket: /bns:deploy to deploy the environment

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 55.81%. Comparing base (4736657) to head (f468807). Report is 466 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #19660      +/-   ##
==========================================
+ Coverage   55.80%   55.81%   +0.01%     
==========================================
  Files         320      320              
  Lines       44250    44281      +31     
==========================================
+ Hits        24693    24717      +24     
- Misses      16998    17006       +8     
+ Partials     2559     2558       -1     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[alswl]

@christianh814 please review this pull-request.