Update OWNERS_ALIASES for gateway-api teams (#4093)

Removed mlavacca from gateway-api-maintainers and added to gateway-api-mesh-leads.

Author: shaneutt

OWNERS_ALIASES

@@ -11,7 +11,6 @@ aliases:
 
   # Reference: https://github.com/kubernetes/org/blob/main/config/kubernetes-sigs/sig-network/teams.yaml
   gateway-api-maintainers:
-    - mlavacca
     - robscott
     - shaneutt
     - youngnick
@@ -21,6 +20,7 @@ aliases:
     - danehans
     - hbagdi
     - jpeach
+    - mlavacca
 
   gateway-api-mesh-leads:
     - howardjohn