feat: add jobs cleaner

[cindyliu-tec]

add a job resource cleaner, when a job's status.completedTime field has value, consider the job is completed, is safe to delete

[cindyliu-tec]

reviewed by myself

[yonahd]

Amazing contribution!
Overall looks great. I'll do a final review after you make the small adjustments to pass gating

[codecov-commenter]

Codecov Report

Attention: 40 lines in your changes are missing coverage. Please review.

Comparison is base (7f0367f) 45.52% compared to head (d617d57) 45.96%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
pkg/kor/jobs.go	56.00%	14 Missing and 8 partials ⚠️
pkg/kor/all.go	0.00%	9 Missing ⚠️
pkg/kor/delete.go	0.00%	7 Missing ⚠️
pkg/kor/multi.go	0.00%	2 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #168      +/-   ##
==========================================
+ Coverage   45.52%   45.96%   +0.43%     
==========================================
  Files          21       22       +1     
  Lines        1990     2080      +90     
==========================================
+ Hits          906      956      +50     
- Misses        930      962      +32     
- Partials      154      162       +8     

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

[yonahd]

LGTM