cc57d656bd
A documentation for `CONF.anycast_evpn_gateway_mode` has
been introduced in [1], but the respective option was never
implemented anywhere, outside of the documentation.
It is the default behavior at the moment, according to [2] and
applied unconditionally
[1] https://review.opendev.org/c/openstack/ovn-bgp-agent/+/906505
[2] 65b5913fdd/ovn_bgp_agent/drivers/openstack/utils/evpn.py (L240-L242)
Change-Id: I28fcc8d245f0d9f5b4771afcf50c0e8ac0cfcbe5