Add `https://pyhf.readthedocs.io/en/v` to linkcheck_ignore

[matthewfeickert]

During release will get

(             faq: line   13) broken    https://pyhf.readthedocs.io/ - 404 Client Error: Not Found for url: https://pyhf.readthedocs.io/en/v0.7.0/

As that doesn't exist yet. So should add it to

pyhf/docs/conf.py

Lines 497 to 505 in 931dd36

	linkcheck_ignore = [
	'cli.html#pyhf-xml2json',
	# https://doi.org/10.31526/lhep.2020.158 is causing linkcheck connection timeouts in CI
	r'https://doi\.org/10\.31526/.*',
	# https://doi.org/10.1051/epjconf/x DOI URLs will periodically generate 500 Server Error
	r'https://doi\.org/10\.1051/epjconf/.*',
	# tags for a release won't exist until it is made, but the release notes need to reference them
	r'https://github.com/scikit-hep/pyhf/releases/tag/.*',
	]

like we did with https://github.com/scikit-hep/pyhf/releases/tag/.* in PR #1705.