CODEOWNERS: misc. updates
CODEOWNERS: misc. updates

* Remove oxyproxy.go references (no longer exists)
* Add owners for new Jenkinsfile / ipcache package.

Signed-off by: Ian Vernon <ian@cilium.io>

eloycoto/cilium,cilium/cilium,scanf/cilium,eloycoto/cilium,michi-covalent/cilium,michi-covalent/cilium,tgraf/cilium,scanf/cilium,tklauser/cilium,scanf/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,scanf/cilium,cilium/cilium,eloycoto/cilium,michi-covalent/cilium,cilium/cilium,scanf/cilium,tgraf/cilium,cilium/cilium,cilium-team/cilium,eloycoto/cilium,scanf/cilium,michi-covalent/cilium,eloycoto/cilium,eloycoto/cilium,tgraf/cilium,cilium/cilium,tgraf/cilium,cilium-team/cilium,scanf/cilium,eloycoto/cilium,tgraf/cilium,tklauser/cilium