release 0.6.1 (#377)

* set the release date

* empty

Author: keewis

docs/whats-new.rst

@@ -2,8 +2,8 @@
 
 What's new
 ==========
-0.6.1 (*unreleased*)
---------------------
+0.6.1 (23 Mar 2026)
+-------------------
 - Properly rename the coordinate units (:pull:`351`).
   By `Justus Magin <https://github.com/keewis>`_.
 - Don't rely on ``xarray``'s default behavior regarding ``attrs`` in :py:func:`pint_xarray.expects` (:issue:`360`, :pull:`367`)