Fix typo

Author: lesteve

CHANGES.md

@@ -7,7 +7,7 @@
 
 - Officially support Python 3.12 and drop support for Python 3.6 and 3.7.
   Dropping support for older Python versions made it possible to simplify the
-  code base signficantly, hopefully making it easier to contribute to and
+  code base significantly, hopefully making it easier to contribute to and
   maintain the project.
   ([PR #517](https://github.com/cloudpipe/cloudpickle/pull/517))