koordlet: support init container for CPUSetAllocator

[zwzhang0107]

Ⅰ. Describe what this PR does

Set cpuset for init container in CPUSetAllocator.

Ⅱ. Does this pull request fix one issue?

#2350

Ⅲ. Describe how to verify it

Ⅳ. Special notes for reviews

V. Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in make test

[codecov]

Codecov Report

Attention: Patch coverage is 37.68116% with 43 lines in your changes missing coverage. Please review.

Project coverage is 65.90%. Comparing base (7a9e18c) to head (8aa668a).
Report is 102 commits behind head on main.

Files with missing lines	Patch %	Lines
...oordlet/runtimehooks/protocol/container_context.go	0.00%	31 Missing ⚠️
pkg/koordlet/runtimehooks/reconciler/reconciler.go	57.14%	6 Missing and 3 partials ⚠️
pkg/koordlet/util/pod.go	75.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2349      +/-   ##
==========================================
- Coverage   65.96%   65.90%   -0.06%     
==========================================
  Files         466      466              
  Lines       54888    54943      +55     
==========================================
+ Hits        36205    36210       +5     
- Misses      16072    16115      +43     
- Partials     2611     2618       +7     

Flag	Coverage Δ
unittests	65.90% <37.68%> (-0.06%)	⬇️

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