scheduler: improve plugin args

[eahydra]

Ⅰ. Describe what this PR does

Improve plugin args by fixing JSON tags and removing unnecessary pointers

• Added missing JSON tags to the plugin arguments to ensure proper serialization.
• Removed pointers from struct fields where direct values are more appropriate, reducing the potential for nil pointer dereferences and simplifying the codebase.

Ⅱ. Does this pull request fix one issue?

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: 2 lines in your changes are missing coverage. Please review.

Comparison is base (afbfea0) 67.09% compared to head (dee52a3) 67.09%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
...cheduler/plugins/coscheduling/plugin_controller.go	0.00%	1 Missing ⚠️
pkg/scheduler/plugins/elasticquota/plugin.go	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1857      +/-   ##
==========================================
- Coverage   67.09%   67.09%   -0.01%     
==========================================
  Files         407      407              
  Lines       45702    45696       -6     
==========================================
- Hits        30664    30659       -5     
+ Misses      12814    12813       -1     
  Partials     2224     2224              

Flag	Coverage Δ
unittests	67.09% <50.00%> (-0.01%)	⬇️

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[hormes]

/lgtm

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