Remove Sphinx as a required dependency

[phlax]

No description provided.

[andy-maier]

Gentle reminder to get this in. We are also hampered by the circular dependency (using pipdeptree).

[mvorisek]

@AA-Turner Please revert, the dep is needed, it has broken our CIs:

Run mv docs/baseline.txt docs/baseline.orig.txt
  mv docs/baseline.txt docs/baseline.orig.txt
  (cd docs && python -m sphinx -T -b html . out 2>&1 | tee baseline.txt)
  sed -i -r 's~[^:]*/docs/([^:]*:)([0-9]+:)?~\1~;t;d' docs/baseline.txt
  shell: sh -e {0}
Running Sphinx v4.5.0

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/sphinx/registry.py", line 438, in load_extension
    metadata = setup(app)
               ^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/sphinxcontrib/applehelp/__init__.py", line 230, in setup
    app.require_sphinx('5.0')
  File "/usr/lib/python3.11/site-packages/sphinx/application.py", line 393, in require_sphinx
    raise VersionRequirementError(version)
sphinx.errors.VersionRequirementError: 5.0

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/sphinx/cmd/build.py", line 272, in build_main
    app = Sphinx(args.sourcedir, args.confdir, args.outputdir,
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/sphinx/application.py", line 219, in __init__
    self.setup_extension(extension)
  File "/usr/lib/python3.11/site-packages/sphinx/application.py", line 380, in setup_extension
    self.registry.load_extension(self, extname)
  File "/usr/lib/python3.11/site-packages/sphinx/registry.py", line 441, in load_extension
    raise VersionRequirementError(
sphinx.errors.VersionRequirementError: The sphinxcontrib.applehelp extension used by this project needs at least Sphinx v5.0; it therefore cannot be built with this version.

Sphinx version error:
The sphinxcontrib.applehelp extension used by this project needs at least Sphinx v5.0; it therefore cannot be built with this version.

[AA-Turner]

You're using Sphinx v4.5.0, which is no longer supported -- if you require Sphinx 4 still, you'll have to pin dependencies.

A

[mvorisek]

@AA-Turner let's do a Sphinx 4.5.1 patch release then fix with https://github.com/sphinx-doc/sphinx/blob/v4.5.0/setup.py#L17 line changed to:

-    'sphinxcontrib-applehelp',
+    'sphinxcontrib-applehelp<=1.0.4',

in 5.x, 6.x, 7.x this needs to be done too to prevent simillar issue in the future