Remove remaining deps on k8s.io/kubernetes

These are mostly helper code for setting up env vars.  There is a single
file copied verbatim, although much of this downward api stuff is a
copy.  We may want to pull this out and do a direct copy of the the code
so it is easier to update and work with upstream to have a shared
package that lives outside of k8s.io/kubernetes for downward api.

.golangci.yml

@@ -6,6 +6,8 @@ run:
   skip-dirs:
     # This directory contains copy code from upstream kubernetes/kubernetes, skip it.
     - internal/kubernetes
+    # This is mostly copied from upstream, rather than fixing that code here just ignore the errors.
+    - internal/podutils
 
 linters:
   enable: