prow: Update the OWNERS file to use the coreos-reviewers alias

This would centralize the maintenance of the approvers list
over in openshift/release.

See openshift/release#54463

This allows us to have permissions to `/override` prow tests among
other things. Currently this is limited to repo administrator but
an OWNERS files makes it easier to manage.
This is a copy from the openshift/os repo.

OWNERS

@@ -0,0 +1,15 @@
+# This file is required in order to control `/approve` and `/lgtm` and related
+# Prow commands on this repo.  It may contain non-Openshift org members and
+# aliases (defined in OWNERS_ALIASES). It will be synced to the
+# `openshift/release/ci-operator` repo where non-Openshift org members will be
+# filtered out and aliases will be expanded.
+
+# See: https://coreos.slack.com/archives/CBN38N3MW/p1654872921259859
+
+# See the OWNERS docs: https://git.k8s.io/community/contributors/guide/owners.md
+
+# This file should mirror the list of users defined on coreos-approvers in:
+# https://github.com/openshift/release/blob/master/OWNERS_ALIASES
+
+approvers:
+  - coreos-approvers