Try switch back to jupyter-server

Following suggestion from
Jupyter-contrib/jupyter_nbextensions_configurator#153
that we need to explicilty enable the configurator.
nbclassic also has hit 1.0, which might help.

Ref 2i2c-org/infrastructure#2380

Dockerfile

@@ -201,6 +201,12 @@ RUN mamba env update -p ${CONDA_DIR} -f /tmp/environment.yml && mamba clean -afy
 ENV NLTK_DATA ${CONDA_DIR}/nltk_data
 RUN mkdir -p ${NLTK_DATA} && python -m textblob.download_corpora
 
+# Explicitly enable jupyter_contrib_nbextension
+RUN jupyter nbclassic-extension install --sys-prefix --py jupyter_nbextensions_configurator --overwrite && \
+    jupyter nbclassic-extension enable --sys-prefix --py jupyter_nbextensions_configurator && \
+    jupyter nbclassic-serverextension install --sys-prefix --py jupyter_nbextensions_configurator --overwrite && \
+    jupyter nbclassic-serverextension enable --sys-prefix --py jupyter_nbextensions_configurator
+
 # Install IRKernel
 RUN r -e "install.packages('IRkernel', version='1.1.1')" && \
     r -e "IRkernel::installspec(prefix='${CONDA_DIR}')"

environment.yml

@@ -30,10 +30,8 @@ dependencies:
   - tensorflow==2.10.0
 
   # Infrastructure things
-  - jupyterlab==3.5.* # Pinned to <3.6, until https://github.com/2i2c-org/infrastructure/issues/2244 is fixed
-  # Pinned until https://github.com/Jupyter-contrib/jupyter_nbextensions_configurator/pull/152 can land
-  # See https://github.com/2i2c-org/infrastructure/issues/2380
-  - nbclassic<0.5
+  - jupyterlab==4.*
+  - nbclassic==1.*
   - retrolab==0.3.*
   - voila==0.3.*
   - nbgitpuller==1.1.*