cleanup csrapproving controller from kube-controller-manager

[zhzhuang-zju]

What type of PR is this?
/kind feature

What this PR does / why we need it:
agentcsrapproving controller is introduced in #5825, from now on, registering member clusters with PULL mode using karmadactl register no longer depends on the csrapproving controller.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[codecov-commenter]

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Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 46.20%. Comparing base (88c3e44) to head (3c91c7d).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/karmadactl/register/register.go	0.00%	1 Missing ⚠️

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Additional details and impacted files

@@           Coverage Diff           @@
##           master    #5874   +/-   ##
=======================================
  Coverage   46.20%   46.20%           
=======================================
  Files         663      663           
  Lines       54580    54580           
=======================================
+ Hits        25218    25221    +3     
+ Misses      27739    27737    -2     
+ Partials     1623     1622    -1     

Flag	Coverage Δ
unittests	46.20% <50.00%> (+<0.01%)	⬆️

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[zhzhuang-zju]

https://github.com/karmada-io/karmada/actions/runs/12001783060/job/33452914814#step:6:3154

/retest

[RainbowMango]

Just a nit, otherwise LGTM.

[RainbowMango]

/retitle cleanup csrapproving controller from kube-controller-manager

[RainbowMango]

/lgtm
/approve

[karmada-bot]

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