DOC: Switch to classic theme #1082

	name: Check links in documentation
	on: [push, pull_request]
	env:
	PYTHONWARNINGS: error
	APT_INSTALL: sudo apt-get install -y --no-install-recommends
	PIP: python -m pip
	SPHINX: python -m sphinx -W --keep-going --color
	jobs:
	linkcheck:
	runs-on: ubuntu-latest
	steps:
	- name: Clone repo
	uses: actions/checkout@v4
	with:
	fetch-depth: 0
	- name: Install pandoc
	run: \|
	$APT_INSTALL pandoc
	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: "3"
	- name: Show Python version
	run: \|
	python --version
	- name: Install Python package
	env:
	# There is still a warning with pip version 24, even though this
	# is supposed to be fixed: https://github.com/pypa/pip/issues/11975
	PYTHONWARNINGS: error,default::DeprecationWarning
	run: \|
	$PIP install .
	- name: Install docs dependencies
	env:
	# There is still a warning with pip version 24, even though this
	# is supposed to be fixed: https://github.com/pypa/pip/issues/11975
	PYTHONWARNINGS: error,default::DeprecationWarning
	run: \|
	$PIP install -r doc/requirements.txt
	- name: Check links
	env:
	# There is a weird warning from jupyter_core (https://github.com/jupyter/jupyter_core/issues/398)
	PYTHONWARNINGS: error,default::DeprecationWarning
	run: \|
	$SPHINX -d _doctrees/ doc/ _build/linkcheck/ -b linkcheck -q
	- name: Upload results
	uses: actions/upload-artifact@v4
	if: ${{ success() \|\| failure() }}
	with:
	name: linkcheck
	path: _build/linkcheck/output.*

Provide feedback