Apply ruff/flake8-bugbear rule B004

B004 Using `hasattr(x, "__call__")` to test if x is callable is unreliable.
     Use `callable(x)` for consistent results.

Author: DimitriPapadopoulos

numpy/lib/_iotools.py

@@ -561,7 +561,7 @@ def upgrade_mapper(cls, func, default=None):
         >>> StringConverter.upgrade_mapper(dateparser, default=defaultdate)
         """
         # Func is a single functions
-        if hasattr(func, '__call__'):
+        if callable(func):
             cls._mapper.insert(-1, (cls._getsubdtype(default), func, default))
             return
         elif hasattr(func, '__iter__'):
@@ -608,7 +608,7 @@ def __init__(self, dtype_or_func=None, default=None, missing_values=None,
                 dtype = np.dtype(dtype_or_func)
             except TypeError:
                 # dtype_or_func must be a function, then
-                if not hasattr(dtype_or_func, '__call__'):
+                if not callable(dtype_or_func):
                     errmsg = ("The input argument `dtype` is neither a"
                               " function nor a dtype (got '%s' instead)")
                     raise TypeError(errmsg % type(dtype_or_func))