Switch back the tox constraint to master

Tempest 46.0.0 release hash is prepared[1] so we can
revert back to use the master constraints by default.

[1] https://review.opendev.org/c/openstack/tempest/+/966350

Change-Id: I80833e28ca650f230235240952f6f42ebaba669e
Signed-off-by: Ghanshyam Maan <gmaan@ghanshyammann.com>
1 file changed