Revert changes for local docs build once related sphinx issue is closed

In MR #2367, changes were made in docs/Makefile to allow docs to be build locally using the make html command. This was needed due to errors that happened when attempting to built the docs with Featuretools installed in editable mode. Docs builds failing in editable mode might be related to an issue with sphinx.

When sphinx issue 10943 (https://github.com/sphinx-doc/sphinx/issues/10943) has been closed and resolved, we should revert the changes that were mode to the Makefile as indicated by the comments here:

.PHONY: html
html:
	# Remove the following line when sphinx issue (https://github.com/sphinx-doc/sphinx/issues/10943) is closed
	python -m pip install .. --quiet --no-dependencies
	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html $(SPHINXOPTS)
	# Remove the following line when sphinx issue (https://github.com/sphinx-doc/sphinx/issues/10943) is closed
	python -m pip install -e .. --quiet --no-dependencies
	@echo
	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
`