DOC: switch back to Sphinx `html` builder #417

Job	Run time
pytest / Determine job matrix	7s
style / Determine skipped pre-commit hooks	11s
doc / linkcheck / Check external links	44s
doc / nb / Execute and build documentation	54s
pytest / Run unit tests (3.10, ubuntu-22.04)	1m 26s
pytest / Run unit tests (3.11, ubuntu-22.04)	1m 2s
pytest / Run unit tests (3.12, ubuntu-22.04)	1m 22s
pytest / Run unit tests (3.7, ubuntu-22.04)	1m 47s
pytest / Run unit tests (3.8, ubuntu-22.04)	1m 31s
pytest / Run unit tests (3.9, ubuntu-22.04, qrules)	4m 20s
pytest / Run unit tests (3.9, macos-12)	1m 24s
style / Run taplo through pre-commit	27s
style / Run local pre-commit hooks	46s
doc / Upload to GitHub Pages	0s
style / Push changes	0s
	16m 1s

Provide feedback