Update maintainers and add kpt codeowners

[nkubala]

No description provided.

[codecov]

Codecov Report

Merging #4686 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4686      +/-   ##
==========================================
- Coverage   73.21%   73.18%   -0.03%     
==========================================
  Files         339      339              
  Lines       13323    13346      +23     
==========================================
+ Hits         9754     9767      +13     
- Misses       2958     2968      +10     
  Partials      611      611              

Impacted Files	Coverage Δ
pkg/skaffold/runner/intent.go	74.19% <0.00%> (-5.12%)	⬇️
pkg/skaffold/runner/new.go	67.11% <0.00%> (ø)
pkg/skaffold/trigger/triggers.go	37.93% <0.00%> (+5.97%)	⬆️

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