Update admins and OWNERS post election 🗳️

In tektoncd#410 I am continuing to try
to make admin/ownership updates after our last election. @dibyom has
joined our governing board so should be added as an admin and owner;
former members should be removed.

Also removed @sbwsg from the top level OWNERS list b/c it looks like he
was added to that to help out with TEP review, and the OWNERS file in
teps/OWNERS should allow him to do this.

OWNERS

@@ -2,10 +2,7 @@
 
 approvers:
 - bobcatfish
-- dlorenc
 - vdemeester
-- kimsterv
 - abayer
-- ImJasonH
 - afrittoli
-- sbwsg
+- dibyom

org/org.yaml

@@ -6,8 +6,8 @@ orgs:
     - tekton-robot
     - thelinuxfoundation
     - vdemeester
-    - imjasonh
     - afrittoli
+    - dibyom
     billing_email: [email protected]
     company: ''
     default_repository_permission: none