[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

CHANGELOG.md

@@ -3,7 +3,6 @@
 This changelog only contains breaking and/or significant changes manually introduced to this repository (using Pull Requests).
 All image manifests can be found in [the wiki](https://github.com/jupyter/docker-stacks/wiki).
 
-
 ## UNRELEASED
 
 Affected: all images.