Fix BindingConstantWithoutTypeAlias for type members with arguments

[Morriar]

This shouldn't be an offense:

Sorbet/BindingConstantWithoutTypeAlias: It looks like you're trying to bind a type to a constant.
To do this, you must alias the type using T.type_alias.
--
  | A = type_member(:in) { { fixed: T.untyped } }
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[paracycle]

Thank you!