DOC: Add a release not for floating.is_integer

doc/release/upcoming_changes/19803.new_feature.rst

@@ -0,0 +1,14 @@
+``is_integer`` is now available to `numpy.floating` and `numpy.integer`
+-----------------------------------------------------------------------
+Based on its counterpart in `float` and `int, the numpy floating point and
+integer types types now support `~float.is_integer`. Returns ``True`` if the
+floating point number is finite with integral value, and ``False`` otherwise.
+
+.. code-block:: python
+
+    >>> np.float32(-2.0).is_integer()
+    True
+    >>> np.float64(3.2).is_integer()
+    False
+    >>> np.int32(-2).is_integer()
+    True