Update CHANGELOG.md

Author: dennisbader

CHANGELOG.md

@@ -100,6 +100,7 @@ but cannot always guarantee backwards compatibility. Changes that may **break co
 ### For developers of the library:
 - Fixed failing docs build by adding new dependency `lxml_html_clean` for `nbsphinx`. [#2303](https://github.com/unit8co/darts/pull/2303) by [Dennis Bader](https://github.com/dennisbader).
 - Bumped `black` from 24.1.1 to 24.3.0. [#2308](https://github.com/unit8co/darts/pull/2308) by [Dennis Bader](https://github.com/dennisbader).
+- Added a Codecov token as repository secret for codecov upload authentication in CI pipelines. [#2309](https://github.com/unit8co/darts/pull/2309) by [Dennis Bader](https://github.com/dennisbader).
 
 ## [0.28.0](https://github.com/unit8co/darts/tree/0.28.0) (2024-03-05)
 ### For users of the library: