Add changelog entry for PR #405

Author: actions-user

docs/changelog.md

@@ -4,6 +4,7 @@ _This project uses semantic versioning_
 
 ## UNRELEASED
 
+- Fix install by adding cloudpickle as required dependency [#405](https://github.com/egraphs-good/egglog-python/pull/405)
 - Add __classdictcell__ to ignored attributes (Python 3.14 support) [#403](https://github.com/egraphs-good/egglog-python/pull/403)
 ## 13.0.0 (2026-03-03)