Add changelog entry

CHANGELOG.md

@@ -1,11 +1,15 @@
 ## [UNRELEASED] - YYYY-MM-DD
 ### Added
 - Add close icon to sidebar on hover ([#454](https://github.com/cbrnr/mnelab/pull/454) by [Benedikt Klöckl](https://github.com/bkloeckl))
+- Add Python 3.13 support ([#457](https://github.com/cbrnr/mnelab/pull/457) by [Clemens Brunner](https://github.com/cbrnr))
 
 ### Changed
 - Change the append dialog appearance to include original indices used for identifying the data ([#449](https://github.com/cbrnr/mnelab/pull/449) by [Benedikt Klöckl](https://github.com/bkloeckl))
 - Include unique dataset indices in sidebar ([#454](https://github.com/cbrnr/mnelab/pull/454) by [Benedikt Klöckl](https://github.com/bkloeckl))
 
+### Removed
+- Remove Python 3.9 support ([#457](https://github.com/cbrnr/mnelab/pull/457) by [Clemens Brunner](https://github.com/cbrnr))
+
 ### Fixed
 - Fix a bug where appending data would not be correctly displayed in the history ([#446](https://github.com/cbrnr/mnelab/pull/446) by [Benedikt Klöckl](https://github.com/bkloeckl))
 - Fix resetting the settings to default values ([#456](https://github.com/cbrnr/mnelab/pull/456) by [Clemens Brunner](https://github.com/cbrnr))