Revert "Mark "test_live_migration_with_trunk" as unstable"

This reverts commit 14399c08a3fa37d510434d1774826b88af16ceb0

The issue reported has been fixed in the following Neutron patches:
* https://review.opendev.org/c/openstack/neutron/+/888769
* https://review.opendev.org/c/openstack/neutron/+/888776

Depends-On: https://review.opendev.org/c/openstack/neutron/+/888776

Related-Bug: #2027605
Change-Id: I6d7850a73bad3066b5f02dbbefe760ee66591e09
1 file changed