New empty whatsnew entry (#8899)

* new empty whatsnew entry

* Update doc/whats-new.rst

Co-authored-by: Deepak Cherian <dcherian@users.noreply.github.com>

---------

Co-authored-by: Deepak Cherian <dcherian@users.noreply.github.com>

Author: TomNicholas

doc/whats-new.rst

@@ -15,6 +15,27 @@ What's New
     np.random.seed(123456)
 
 
+.. _whats-new.2024.04.0:
+
+v2024.04.0 (unreleased)
+-----------------------
+
+New Features
+~~~~~~~~~~~~
+
+
+Breaking changes
+~~~~~~~~~~~~~~~~
+
+
+Bug fixes
+~~~~~~~~~
+
+
+Internal Changes
+~~~~~~~~~~~~~~~~
+
+
 .. _whats-new.2024.03.0:
 
 v2024.03.0 (Mar 29, 2024)