`sentry_user` not PII scrubbed

[Dav1dde]

sentry_user added by Relay is not PII scrubbed if the user is PII scrubbed.

"user":{
   "ip_address":null,
   "geo":{
      "country_code":"US",
      "city":"New York",
      "subdivision":"New York",
      "region":"United States"
   },
   "sentry_user":"ip:111.222.222.111"
},

The PII scrubbing metadata on the event:

"_meta":{
   "user":{
      "ip_address":{
         "":{
            "rem":[
               [
                  "@ip:replace",
                  "s",
                  0,
                  4
               ],
               [
                  "@anything:remove",
                  "x"
               ]
            ],
            "len":15
         }
      }
   }
},