FIX: Add missing deps for virtualenv environments (#253)

[Steve-Roderick]

* Add `cartopy` for test `examples/notebooks/Multi-Volume-Concatenation.ipynb`.
* Add `boto3` for test `examples/notebooks/Read-plot-Sigmet-data-from-AWS.ipynb`.
* Add `zarr` for test `examples/notebooks/multiple-sweeps-into-volume-scan.ipynb`.
* Add `s3fs` for test `examples/notebooks/Read-plot-Sigmet-data-from-AWS.ipynb`.
* Add `open_radar_data` for sample data sets used in unittests.
* Add `notebook` and `nbconvert` for unittesting jupyter notebooks.
* Add note to CONTRIBUTING.md referencing OS dependency for `ffmpeg`

• Closes Several dependencies are missing when running the tests #253

[Steve-Roderick]

First time contributor here.

• I did not add any new tests as I think adding a Dockerfile and using docker or podman to verify the environment is probably overkill.
• I did not edit the history.md file because this change is not really a functional change. Let me know if you'd like me to add a line item to history.md.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.58%. Comparing base (059b5bf) to head (8458255).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #274   +/-   ##
=======================================
  Coverage   93.58%   93.58%           
=======================================
  Files          26       26           
  Lines        5082     5082           
=======================================
  Hits         4756     4756           
  Misses        326      326           

Flag	Coverage Δ
notebooktests	79.24% <ø> (ø)
unittests	93.17% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[kmuehlbauer]

Thanks @Steve-Roderick for this PR. Until there will, eventually, be an established standard on how to provide these kind of things within pyproject.toml this is a good way to provide the necessary information.

And, although this is no change in functionality, it fixes an issue and is making user experience better. So please add an entry to history.md.

[Steve-Roderick]

Sounds good - thank you.

• I added an entry to the history.md
• Previously one test was failing because I did not pin the zarr dependency to 2.x and if you use zarr 3.x there is a test failure.
  --
  I forced pushed an amended commit.

Thanks again.

[kmuehlbauer]

Thanks @Steve-Roderick!