🌱 Clean up owners

This change removes fillzpp from maintainters, as there was no activity
since September 2024: https://github.com/kubernetes-sigs/controller-runtime/issues?q=commenter%3Afillzpp

Author: alvaroaleman

OWNERS_ALIASES

@@ -17,8 +17,7 @@ aliases:
   - vincepri
 
   # non-admin folks who can approve any PRs in the repo
-  controller-runtime-approvers:
-  - fillzpp
+  controller-runtime-approvers: []
 
   # folks who can review and LGTM any PRs in the repo (doesn't
   # include approvers & admins -- those count too via the OWNERS