Update CHANGELOG.md

Author: alexcjohnson

CHANGELOG.md

@@ -7,8 +7,6 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 - [#2610](https://github.com/plotly/dash/pull/2610) Load plotly.js bundle/version from plotly.py
 
-## UNRELEASED
-
 ## Added
 
 - [#2630](https://github.com/plotly/dash/pull/2630) New layout hooks in the renderer