remove widgets and nbextensions

[chrisroadmap]

On install using make venv I get the following error:

Jupyter command `jupyter-nbextension` not found.
make: *** [venv] Error 1

If we go to the Makefile we have the following lines:

        [ -d $(VENV_DIR) ] || python3 -m venv $(VENV_DIR)
        $(VENV_DIR)/bin/pip install --upgrade pip wheel
        $(VENV_DIR)/bin/pip install -e .[dev]
        $(VENV_DIR)/bin/jupyter nbextension enable --py widgetsnbextension

Thus, ciceroscm is being successfully installed, but the jupyter nbextension line is failing.

The jupyter nbextension command is out of date moving to JupyterLab (https://bbs.archlinux.org/viewtopic.php?id=292074). I can't easily find a command that replaces this. However, I don't believe that the examples in the notebooks directory use anything fancy, so it could probably be safely removed from the Makefile and the relevant dependencies deleted from setup.py. This pull request does this.

I'm using python 3.10 on Linux.

Confirmed that tests run and that notebooks perform as expected.

• ~[ ] Tests added~
• ~[ ] Documentation added~
• ~[ ] Example added (in the documentation, to an existing notebook, or in a new notebook)~
• [x] Description in CHANGELOG.rst added (single line such as: (`#XX <https://github.com/ciceroOslo/ciceroscm/pull/XX>`_) Added feature which does something)

[maritsandstad]

I actually also did this in here: #131, I think, but the changelog was something I hadn't fixed yet. Do you mind if I just merge this in there, @chrisroadmap? Was planning to put a tag to make it a minor bugfix-release

[chrisroadmap]

Ah my bad, I just skimmed the titles of the issues and PRs. Sure, go ahead and close this and feel free to use my change log text.

[maritsandstad]

No reason to apologise, it's my fault for doing a two-issue in one thing :-)