fix: update copy

Author: kgryte

src/array_api_stubs/_draft/data_type_functions.py

@@ -34,7 +34,7 @@ def astype(
         -   If ``dtype`` is a data type kind,
 
             -   If the data type of ``x`` belongs to the specified data type kind, the function must return an array having the same data type as ``x``.
-            -   If the data type of ``x`` does not belong to the specified data type kind, the function cast the input array to a data type of the specified data type kind according to type promotion rules (see :ref:`type-promotion`) and the casting rules documented below.
+            -   If the data type of ``x`` does not belong to the specified data type kind, the function must cast the input array to a data type of the specified data type kind according to type promotion rules (see :ref:`type-promotion`) and the casting rules documented below.
 
                 -   When applying type promotion rules, the returned array must have the lowest-precision data type belonging to the specified data type kind to which the data type of ``x`` promotes (e.g., if ``x`` is ``float32`` and the data type kind is ``'complex floating'``, then the returned array must have the data type ``complex64``; if ``x`` is ``uint16`` and the data type kind is ``'signed integer'``, then the returned array must have the data type ``int32``).
                 -   When type promotion rules are not specified between the data type of ``x`` and the specified data type kind (e.g., ``int16`` and ``'real floating'``) and there exists one or more data types belonging to the specified data kind in which the elements in ``x`` can be represented exactly (e.g., ``int32`` and ``float64``), the function must return an array having the smallest data type (in terms of range of values) capable of precisely representing the elements of ``x`` (e.g., if ``x`` is ``int16`` and the data type kind is ``'complex floating'``, then the returned array must have the data type ``complex64``; if ``x`` is `bool`` and the data type kind is ``integral``, then the returned array must have the data type ``int8``).