Prune reviewers on cmd/kubelet/app

cmd/kubelet/app/OWNERS

 reviewers:
-- thockin
-- lavalamp
 - smarterclayton
-- wojtek-t
-- bgrant0607
-- deads2k
 - yujuhong
-- brendandburns
 - derekwaynecarr
-- caesarxuchao
 - vishh
 - mikedanese
 - liggitt
 - bprashanth
-- gmarek
-- erictune
-- davidopp
-- pmorie
-- sttts
-- quinton-hoole
 - dchen1107
-- saad-ali
-- zmerlynn
 - luxas
 - justinsb
-- pwittrock
-- roberthbailey
 - ncdc
 - timstclair
 - yifan-gu
-- eparis
-- mwielgus
 - feiskyer
-- jlowdermilk
-- piosz
-- jbeda
-- dims
-- errordeveloper
-- madhusudancs
-- krousey