DeviceManager is GA now

Author: SergeyKanzhelev

keps/sig-node/3573-device-plugin/kep.yaml

@@ -5,7 +5,7 @@ authors:
   - "@jiayingz"
   - "@swatisehgal" # for translation to latest KEP template, PRR questionnaire and GA graduation
 owning-sig: sig-node
-status: implementable
+status: implemented
 creation-date: 2022-10-02
 approvers:
   - "@dawnchen"