fix: delete plugins in parallel to avoid hitting timeouts

[ahmad-ibra]

When a certain threshold is passed in number of plugins running, plugin helm chart deletion via the validator-cleanup job fails due to timeouts. The idea hear is to parallelize the chart deletions via goroutines to reduce the risk of this happening.

[codecov]

Codecov Report

Merging #141 (97978e9) into main (3ae7b70) will increase coverage by 0.66%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #141      +/-   ##
==========================================
+ Coverage   55.17%   55.84%   +0.66%     
==========================================
  Files           9        9              
  Lines         850      856       +6     
==========================================
+ Hits          469      478       +9     
+ Misses        354      353       -1     
+ Partials       27       25       -2     

Files	Coverage Δ
internal/controller/validatorconfig_controller.go	76.88% <100.00%> (+2.00%)	⬆️

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[TylerGillson]

Let's leave the timeout alone for now and keep adding plugins until it breaks again 😝

I say that because the full timeout is respected regardless of the # of plugins. So it would suck if users had to wait 15s for helm uninstall if there's only 1 plugin. I'd rather wait and find out how far these changes will get us.