Enable similarity and locker (#4435)

* turn on similarity

* turn on locker

.github/locker.yml

@@ -2,5 +2,5 @@
   daysAfterClose: 45,
   daysSinceLastUpdate: 3,
   ignoredLabels: [],
-  perform: false
+  perform: true
 }

.github/similarity.yml

@@ -1,5 +1,5 @@
 {
-  perform: false,
+  perform: true,
   whenCreatedByTeam: true,
   comment: "Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:\n${potentialDuplicates}"
 }