Fix retrieval and display of jupyter password

[ckunki]

Currently file ansible/roles/jupyter/templates/etc/update-motd.d/999-jupyter reads the password from file jupyter_server_config_file = /root/.jupyter/jupyter_server_config.json.

Since update of Jupyterlab from version 3.4.3 to version 4.0.6 in file ansible/roles/jupyter/files/requirements_jupyter.txt the file format has changed.

Current content:

{ "IdentityProvider": {
    "hashed_password": "argon2:$argon2id$v=19$m=10240,t=10,p=8$a7.../mF+ag.../jm..."
  } }

This makes test test/ci/test_ci.test_jupyter_password_message_shown() fail with cat: /var/run/motd.dynamic: No such file or directory.
Therefore the test is current disabled.

The current ticket requests to

• fix or remove retrieval of the password in 999-jupyter
• either re-enable and fix the test case or remove it