CP/DP Split: fix label updates

[sjberman]

Problem: Updating labels/annotations on the Gateway did not propagate to some resources.

Solution: Ensure that labels/annotations are set when updating resources.

Also removed some unnecessary conditions and the "connection" agent feature.

Testing: Verified that labels/annotations are updated properly

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

[codecov]

Codecov Report

Attention: Patch coverage is 81.57895% with 7 lines in your changes missing coverage. Please review.

Project coverage is 86.77%. Comparing base (dca6b4b) to head (d9ab5f9).
Report is 1 commits behind head on change/control-data-plane-split.

Files with missing lines	Patch %	Lines
internal/mode/static/provisioner/setter.go	81.08%	7 Missing ⚠️

Additional details and impacted files

@@                         Coverage Diff                         @@
##           change/control-data-plane-split    #3370      +/-   ##
===================================================================
+ Coverage                            86.65%   86.77%   +0.12%     
===================================================================
  Files                                  129      129              
  Lines                                14855    14862       +7     
  Branches                                62       62              
===================================================================
+ Hits                                 12872    12897      +25     
+ Misses                                1834     1817      -17     
+ Partials                               149      148       -1     

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