Update to JupyterLab 4 and JupyterLite 0.2.0 (Backport #155 on 0.x)

[martinRenou]

• Update to JupyterLab 4 and JupyterLite 0.2.0

• Add jupyterlite_core_alpha channel

• add alpha channel

• update yarnrc

• update yarn.lock

• update jupyterlab dependency

• add nodejs

• fix addon import

• more setup-micromamba updates

• add mamba

• Bump to 0.2.0a1

• install lab 4 on CI

[github-actions[bot]]

:point_left: Try it on ReadTheDocs