chore: Graceful handling of panic in application set controller reconcile (#20935)

[andrii-korotkov-verkada]

Closes #20935

Recover from panic if it happens, similar to how application controller does it.

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]

❌ Preview Environment deleted from Bunnyshell

Available commands (reply to this comment):

• 🚀 /bns:deploy to deploy the environment

[codecov]

Codecov Report

Attention: Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.

Project coverage is 55.02%. Comparing base (32cc663) to head (e6bf5b0).
Report is 11 commits behind head on master.

Files with missing lines	Patch %	Lines
...cationset/controllers/applicationset_controller.go	20.00%	7 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #20940      +/-   ##
==========================================
- Coverage   55.04%   55.02%   -0.03%     
==========================================
  Files         324      324              
  Lines       55421    55465      +44     
==========================================
+ Hits        30504    30517      +13     
- Misses      22303    22328      +25     
- Partials     2614     2620       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ishitasequeira]

LGTM!!