Avoid extra array allocation

ee/app/models/concerns/ee/mentionable.rb

@@ -8,7 +8,9 @@ module EE
 
     override :extracted_mentionables
     def extracted_mentionables(refs)
-      super + refs.epics
+      super.concat(
+        refs.epics
+      )
     end
   end
 end

ee/app/models/concerns/ee/mentionable/reference_regexes.rb

@@ -10,10 +10,9 @@ module EE
 
         override :other_patterns
         def other_patterns
-          [
-            ::Epic.reference_pattern,
-            *super
-          ]
+          super.unshift(
+            ::Epic.reference_pattern
+          )
         end
       end
     end