- Show file checkboxes by default in the file browser [#6377](https://github.com/jupyter/notebook/pull/6377) ([@jtpio](https://github.com/jtpio))
- Remove blank space at the bottom of the notebook [#6376](https://github.com/jupyter/notebook/pull/6376) ([@jtpio](https://github.com/jtpio))
- Add a label to the upload button [#6374](https://github.com/jupyter/notebook/pull/6374) ([@jtpio](https://github.com/jtpio))
- Update to JupyterLab 4.0.0a24 [#6371](https://github.com/jupyter/notebook/pull/6371) ([@jtpio](https://github.com/jtpio))
- Initialize handler page_config from Server traitlets [#6366](https://github.com/jupyter/notebook/pull/6366) ([@bollwyvl](https://github.com/bollwyvl))
- Add project URLs to setup.cfg [#6346](https://github.com/jupyter/notebook/pull/6346) ([@tlinhart](https://github.com/tlinhart))
- Update to JupyterLab 4.0.0a23 [#6336](https://github.com/jupyter/notebook/pull/6336) ([@jtpio](https://github.com/jtpio))
### Bugs fixed
- Fix opening JupyterLab from Notebook [#6379](https://github.com/jupyter/notebook/pull/6379) ([@jtpio](https://github.com/jtpio))
### Maintenance and upkeep improvements
- Add UI tests for a simple notebook [#6380](https://github.com/jupyter/notebook/pull/6380) ([@jtpio](https://github.com/jtpio))
- Bump async from 2.6.3 to 2.6.4 in /ui-tests [#6370](https://github.com/jupyter/notebook/pull/6370) ([@dependabot](https://github.com/dependabot))
- Fix build workflow on CI [#6369](https://github.com/jupyter/notebook/pull/6369) ([@jtpio](https://github.com/jtpio))
- Add pytest and handle warnings [#6338](https://github.com/jupyter/notebook/pull/6338) ([@blink1073](https://github.com/blink1073))
- Add flake8 and git-blame-ignore-revs [#6337](https://github.com/jupyter/notebook/pull/6337) ([@blink1073](https://github.com/blink1073))
- Run Autoformatters [#6335](https://github.com/jupyter/notebook/pull/6335) ([@blink1073](https://github.com/blink1073))
- Bump minimist from 1.2.5 to 1.2.6 [#6334](https://github.com/jupyter/notebook/pull/6334) ([@dependabot](https://github.com/dependabot))
- Bump minimist from 1.2.5 to 1.2.6 in /ui-tests [#6333](https://github.com/jupyter/notebook/pull/6333) ([@dependabot](https://github.com/dependabot))
- Bump ansi-regex from 3.0.0 to 3.0.1 in /ui-tests [#6332](https://github.com/jupyter/notebook/pull/6332) ([@dependabot](https://github.com/dependabot))