Prepare changelog for release 0.6.0-3

debian/changelog

+python-multipledispatch (0.6.0-3) unstable; urgency=medium
+
+  * Fix autopkgtest (missing dependency)
+  * Fix d/watch
+  * Bump Standards-Version to 4.6.0 (no changes needed)
+  * Bump debhelper compatibility to 13
+
+ -- Christian Kastner <ckk@debian.org>  Thu, 17 Feb 2022 22:00:15 +0100
+
 python-multipledispatch (0.6.0-2) unstable; urgency=medium
 
   [ Ondřej Nový ]