zuul: Drop neutron-linuxbridge-tempest job

Neutron has deprecated linuxbridge support and is only doing reduced
testing for the neutron-linuxbridge-tempest job, so we need no longer
run it in devstack, even less gate on it.

Signed-off-by: Dr. Jens Harbott <harbott@osism.tech>
Change-Id: Ie1a8f978efe7fc9b037cf6a6b70b67d539d76fd6
1 file changed