remove mattia

there is no possibility to set emeritus on subprojects, at least
the generator fails.

Author: aojea

sigs.yaml

@@ -2359,9 +2359,6 @@ sigs:
           - https://raw.githubusercontent.com/kubernetes/kubernetes/master/pkg/proxy/OWNERS
           - https://raw.githubusercontent.com/kubernetes/kubernetes/master/staging/src/k8s.io/cloud-provider/controllers/service/OWNERS
         leads:
-          - github: mlavacca
-            name: Mattia Lavacca
-            company: Kong
           - github: robscott
             name: Rob Scott
             company: Google