Add PR number to whats-new

Co-authored-by: Claude <noreply@anthropic.com>

Author: headtr1ck

doc/whats-new.rst

@@ -59,7 +59,7 @@ Breaking Changes
   is now 3.12, in line with xarray's
   :ref:`minimum dependency policy <mindeps_policy>` (:pull:`11649`).
   By `Michael Niklas <https://github.com/headtr1ck>`_.
-- The minimum versions of some dependencies were changed:
+- The minimum versions of some dependencies were changed (:pull:`11728`):
 
   ===================== =========  =======
    Package                    Old      New
@@ -4244,7 +4244,7 @@ New Features
 Breaking changes
 ~~~~~~~~~~~~~~~~
 
-- The minimum versions of some dependencies were changed:
+- The minimum versions of some dependencies were changed (:pull:`11728`):
 
   ========================== =========  ========
    Package                         Old      New
@@ -4891,7 +4891,7 @@ New Features
 
 Breaking changes
 ~~~~~~~~~~~~~~~~
-- The minimum versions of some dependencies were changed:
+- The minimum versions of some dependencies were changed (:pull:`11728`):
 
   =============== ====== ====
   Package         Old    New
@@ -5307,7 +5307,7 @@ New Features
 
 Breaking changes
 ~~~~~~~~~~~~~~~~
-- The minimum versions of some dependencies were changed:
+- The minimum versions of some dependencies were changed (:pull:`11728`):
 
   ============ ====== ====
   Package      Old    New