Disable 'xmllint' checks in a2x (#16317)
Disable 'xmllint' checks in a2x (#16317)

It brings in a libxml2 dep to the docs build
require. The a2x default of xmllint invocation
attempts to make outgoing requests to download
XML DTD's, despite a2x using the '--nonet' flag.
thaim/ansible,thaim/ansible