Add Performance/ZipWithoutBlock rubocop rule

This rule was added in rubocop-performance 1.24.

We currently don't have code where it'd be relevant, but it's a nice
rule to have if we ever write `something.map { |element| [element] }`.

.rubocop.yml

@@ -386,6 +386,9 @@ Performance/StartWith:
 Performance/Sum:
   Enabled: true
 
+Performance/ZipWithoutBlock:
+  Enabled: true
+
 Rails/ActionControllerFlashBeforeRender:
   Enabled: true