MAINT: update sphinx to include sphinx v4

[mmcky]

@AakashGfude I am trying to upgrade this package to be compatible with sphinx4 but it has a testing dependency on jupyter-book. Having an upstream dependency makes these sort of updates difficult. Can we link up sometime to discuss having this dependency?

[codecov[bot]]

Codecov Report

Merging #75 (9a2db12) into master (43e48a3) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master      #75   +/-   ##
=======================================
  Coverage   91.45%   91.45%           
=======================================
  Files           4        4           
  Lines         316      316           
=======================================
  Hits          289      289           
  Misses         27       27           

Flag	Coverage Δ
pytests	91.45% <100.00%> (ø)

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

Impacted Files	Coverage Δ
sphinx_jupyterbook_latex/transforms.py	91.70% <100.00%> (ø)

[mmcky]

@AakashGfude @chrisjsewell I have moved the myst_nb pin to only support myst_nb >= 0.13 as I have updated the fixtures to include:

classes="tex2jax_ignore mathjax_ignore"

which comes from myst-parser update

https://myst-parser.readthedocs.io/en/latest/syntax/optional.html#mathjax-and-math-parsing

[mmcky]

@AakashGfude what is the use of myst in the options listing in setup.cfg. It looks like I had to add it to testing anyway?

[mmcky]

• [x] add jupyter-book test sets to jupyter-book:sphinx4
• [x] Switch "building PDF of JupyterBook Docs" to use a sphinx build in github actions
• [x] @AakashGfude can you cast an eye over the updated fixtures to double check the updates are expected

[mmcky]

@AakashGfude @chrisjsewell are there any good sphinx projects (that are reasonably complex) that we can test against for the github action? I can make up a test repo if we need to but thought I would check.

I think removing any jupyter-book tests from this repo makes sense so I have:

• [x] moved the jupyter-book test to jupyter-book
• [x] updating the pdf.yml workflow for github actions.

Update: I have decided to remove the .github/workflow/pdf.yml as we can really just leave tests for the test suite. It is also already being done at the jupyter-book level here

[AakashGfude]

@mmcky looks good to me.

[choldgraf]

Is this waiting on anything?