Update sphinx to 4.2.0

[trsvchn]

Fixes #2224

Description:

Update sphinx to 4.2.0

Note: before merging:

• Merge this: Update deprecated method pytorch-ignite/sphinxcontrib-versioning#3
• Fix .github/workflows/install_docs_deps.sh

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[ydcjeff]

When merging this PR, I would suggest to add -j auto -WT --keep-going --color in

ignite/docs/Makefile

Line 5 in ed5e1dd

SPHINXOPTS =

• -j auto is using available cpus.
• -W is Turn warnings into errors. This means that the build stops at the first warning and sphinx-build exits with exit status 1.
• -T is Display the full traceback when an unhandled exception occurs. Otherwise, only a summary is displayed and the traceback information is saved to a file for further analysis.
• --keep-going is With -W option, keep going processing when getting warnings to the end of build, and sphinx-build exits with exit status 1.
• --color enables color output.

And remove SPHINXOPTS defined under .github directory.

Taken from pytorch.

[vfdev-5]

@trsvchn can you share your findings about sphinx 4.X here please and move forward with this PR.

[trsvchn]

When merging this PR, I would suggest to add -j auto -WT --keep-going --color in

ignite/docs/Makefile

Line 5 in ed5e1dd

SPHINXOPTS =

* `-j auto` is using available cpus.

* `-W` is Turn warnings into errors. This means that the build stops at the first warning and sphinx-build exits with exit status 1.

* `-T` is Display the full traceback when an unhandled exception occurs. Otherwise, only a summary is displayed and the traceback information is saved to a file for further analysis.

* `--keep-going` is With -W option, keep going processing when getting warnings to the end of build, and sphinx-build exits with exit status 1.

* `--color` enables color output.

And remove SPHINXOPTS defined under .github directory.

Taken from pytorch.

Yeah, That's good idea!

[trsvchn]

@trsvchn can you share your findings about sphinx 4.X here please and move forward with this PR.

Similar idea to upgrade sphinx, but they ended up with 3.5.4
pytorch/pytorch#61601

Looks like new sphinx generates html with another structure, and the theme css should be adjusted
For example (sphinx 4.2.0 on the left)

[trsvchn]

kindly asking @ydcjeff for the final review! :)

[vfdev-5]

@trsvchn we have "Notes" folded but others unfolded, can we make all unfolded ? Code snippets are more compacted:

• https://deploy-preview-2261--pytorch-ignite-preview.netlify.app/generated/ignite.engine.engine.engine#ignite.engine.engine.Engine
  vs
• https://pytorch.org/ignite/generated/ignite.engine.engine.Engine.html#ignite.engine.engine.Engine

Otherwise, OK for me

[trsvchn]

Snippets are now ok, thanks for spotting that!
Unlike problem with unfolding by default. Need some time...

[vfdev-5]

LGTM, thanks @trsvchn !

I think we can pause on unfolding Notes for this PR.

[oke-aditya]

Hi sorry for not helping on this :(
This seems great!
Even pytorch domain libraries don't use 4.2 !