Remove dulek from approvers (#3099)

I don't work with OpenStack or cloud providers anymore and you can
clearly see that my involvement with the project is almost non-existent.
This commit removes me from approvers and reviewers of the project.

Author: dulek

OWNERS

@@ -3,13 +3,12 @@ emeritus_approvers:
 - lingxiankong
 - ramineni
 - jichenjc
-approvers:
 - dulek
+approvers:
 - kayrus
 - stephenfin
 - zetaab
 reviewers:
-- dulek
 - kayrus
 - stephenfin
 - zetaab