build, ci: upgrade build and ci setups

[iisakkirotko]

Pull Request Template

Description

Spiritual successor to #111. Does a few things

• Migrates to a pyproject.toml based build process instead of a setup.py based one.
• Bumps the NodeJS version on CI
• Fixes visual regression tests
• Fixes Python 3.7 tests

Todo:

• Fix visual regression tests - failing due to a small change in how axis labels are rendered.
• Python 3.6 tests need to be removed or modified - because hatch_jupyter_builder has only ever supported Python >= 3.7, we can't build on Python 3.6. However, any built wheel should also work on Python 3.6 so pre-building a wheel and then using it for py36 tests should work

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 44.44%. Comparing base (7b90b9d) to head (70dda5d).
Report is 13 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #113      +/-   ##
==========================================
- Coverage   50.00%   44.44%   -5.56%     
==========================================
  Files           7        8       +1     
  Lines         140      189      +49     
==========================================
+ Hits           70       84      +14     
- Misses         70      105      +35     

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