[release-1.10] eliminate short-circuiting in logic to add/remove finalizers

[k8s-infra-cherrypick-robot]

This is an automated cherry-pick of #4211

/assign nojnhuh

Fixed a bug potentially causing finalizers not to be applied in some cases

[nojnhuh]

/kind bug

[codecov]

Codecov Report

Attention: 6 lines in your changes are missing coverage. Please review.

Comparison is base (47695c8) 54.36% compared to head (f47fd94) 54.36%.
Report is 1 commits behind head on release-1.10.

Additional details and impacted files

@@              Coverage Diff              @@
##           release-1.10    #4222   +/-   ##
=============================================
  Coverage         54.36%   54.36%           
=============================================
  Files               186      186           
  Lines             18896    18898    +2     
=============================================
+ Hits              10272    10274    +2     
  Misses             8069     8069           
  Partials            555      555           

Files	Coverage Δ
controllers/azuremanagedcontrolplane_controller.go	20.50% <0.00%> (-0.11%)	⬇️
controllers/helpers.go	56.15% <0.00%> (-0.09%)	⬇️

... and 1 file with indirect coverage changes

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[mboersma]

/lgtm
/approve

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 898bc79802ef85d8bca8bd85319e31a6336a05b6

[k8s-ci-robot]

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