Update to jupyterlite 0.6

Author: SylvainCorlay

.github/workflows/deploy-github-page.yml

@@ -141,7 +141,7 @@ jobs:
         shell: bash -l {0}
         run: |
           micromamba activate xeus-lite-host
-          python -m pip install jupyterlite-xeus
+          python -m pip install jupyterlite-xeus=4.0.0rc0
           jupyter lite build \
               --XeusAddon.prefix=${{ env.PREFIX }} \
               --contents README.md \