fix Dockerfile

2 jobs for master in 3 seconds
Status Job ID Name Coverage
  Deps
failed #24365
shell
deps

00:00:03

 
  Pages
skipped #24366
docker
pages
 
Name Stage Failure
failed
deps Deps
 ---> f3ab2605e3d3
Step 8/11 : ENV PATH /opt/conda/envs/$(head -1 /tmp/environment.yml | cut -d' ' -f2)/bin:$PATH
---> Using cache
---> 05a8891753f0
Step 9/11 : RUN python3 -m bash_kernel.install
---> Running in e6e75352e9b6
/opt/conda/bin/python3: Error while finding module specification for 'bash_kernel.install' (ModuleNotFoundError: No module named 'bash_kernel')
The command '/bin/sh -c python3 -m bash_kernel.install' returned a non-zero code: 1
ERROR: Job failed: exit status 1