DOC: only change tp_name on CPython [skip azp][skip actions][skip cirrus]

Author: mattip

doc/source/conf.py

@@ -52,8 +52,12 @@ class PyTypeObject(ctypes.Structure):
     ]:
         typ = getattr(numpy, name)
         c_typ = PyTypeObject.from_address(id(typ))
-        c_typ.tp_name = _name_cache[typ] = b"numpy." + name.encode('utf8')
-
+        if sys.implementation.name == 'cpython':
+            c_typ.tp_name = _name_cache[typ] = b"numpy." + name.encode('utf8')
+        else:
+            # It is not guarenteed that the c_typ has this model on other
+            # implementations
+            _name_cache[typ] = b"numpy." + name.encode('utf8')
 
 replace_scalar_type_names()