[EQL] remove unneeded __contains__ override.

Author: AbdelrhmanBassiouny

src/krrood/entity_query_language/symbolic.py

@@ -420,9 +420,6 @@ def __call__(self, *args, **kwargs) -> CanBehaveLikeAVariable[T]:
     def __eq__(self, other) -> Comparator:
         return Comparator(self, other, operator.eq)
 
-    def __contains__(self, item) -> Comparator:
-        return Comparator(item, self, operator.contains)
-
     def __ne__(self, other) -> Comparator:
         return Comparator(self, other, operator.ne)