Handle RuleDelayed in MapAt over Association expressions

Author: Li-Xiang-Ideal

mathics/eval/functional/apply_fns_to_lists.py

@@ -38,9 +38,9 @@ def map_at_replace_one(elements: Iterable, index: ListExpression, i: int) -> lis
             raise PartRangeError
         new_elements = list(elements)
         replace_element = elements[j]
-        if hasattr(replace_element, "head") and replace_element.head is SymbolRule:
+        if replace_element.has_form(("Rule", "RuleDelayed"), 2):
             new_elements[j] = Expression(
-                SymbolRule,
+                replace_element.get_head(),
                 replace_element.elements[0],
                 Expression(f, replace_element.elements[1]),
             )