Update Nathan Herz email

Author: natherz97

sigs.yaml

@@ -4028,7 +4028,7 @@ committees:
     - github: natherz97
       name: Nathan Herz
       company: Amazon
-      email: natherz@amazon.com
+      email: nathan.herz97@gmail.com
     - github: puerco
       name: Adolfo García Veytia
       company: Carabiner Systems, Inc