removing repeated unrecheable code

Author: mmatera

mathics/eval/arithmetic.py

@@ -463,13 +463,6 @@ def append_last():
         elements_properties=ElementsProperties(False, False, True),
     )
 
-    elements.sort()
-    return Expression(
-        SymbolPlus,
-        *elements,
-        elements_properties=ElementsProperties(False, False, True),
-    )
-
 
 def eval_Power_number(base: Number, exp: Number) -> Optional[Number]:
     """