Merge pull request #8418 from BenTheElder/sig-ui-lead-emails

add sig ui lead emails

Author: k8s-ci-robot

sigs.yaml

@@ -3391,12 +3391,15 @@ sigs:
     - github: floreks
       name: Sebastian Florek
       company: Plural
+      email: [email protected]
     - github: maciaszczykm
       name: Marcin Maciaszczyk
       company: Plural
+      email: [email protected]
     - github: shu-mutou
       name: Shu Muto
       company: NEC
+      email: [email protected]
     emeritus_leads:
     - github: danielromlein
       name: Dan Romlein