Jupyterlab-fonts

- see `3.0.0` alpha releases below

- hoist, update Lab 3/4 compatibility methods to public API
- fix notebook metadata watching when no app-level styles are present

- add more Lab 3/4 compatibility methods

- remove tests and duplicated assets from wheel
- fix npm version numbers
- lazily load JSS and friends

- Support JupyterLab 4
- Support Notebook 7
- Fix global typefaces
- Adds UI font to the editor, commands, and menus
- Adds Atkinson Hyperlegible font

- Fix some errors when disposing notebooks
- Normalize generated CSS
- Allow for dereferencing local asset `url()`s for `import`, etc.