MAINT: fix typo

Author: lucascolley

src/array_api_extra/_funcs.py

@@ -123,9 +123,6 @@ def expand_dims(
         )
         raise IndexError(err_msg)
     axis = tuple(dim % ndim for dim in axis)
-    if len(set(axis)) != len(axis):
-        err_msg = "Duplicate dimensions specified in `axis`."
-        raise ValueError(err_msg)
     if len(set(axis)) != len(axis):
         err_msg = "Duplicate dimensions specified in `axis`."
         raise ValueError(err_msg)