Remove docs on long gone nova scheduler filters
Remove docs on long gone nova scheduler filters

Removes the docs for the GroupAffinityFilter and
GroupAntiAffinityFilter which were removed way back
in Kilo:

c4eec3de4b218a03e3e1101079d42b2ad6888a63

Change-Id: I8f0b7b99457e39f9b0cf6682f833db769fba6591

openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals