bpo-44752: Make rlcompleter not call `@property` methods (GH-27401)

bpo-44752: Make rlcompleter not call `@property` methods (GH-27401)

* rlcompleter was calling these methods to identify whether to add
  parenthesis to the completion, based on if the attribute is callable.
* for property objects, completion with parenthesis are never desirable.
* property methods with print statements behaved very strangely, which
  was especially unfriendly to language newcomers. <tab> could suddenly
  produce output unexpectedly.