Switch to the master constraint in tox.ini

To releas a new tag for Tempest 2023.1, we modified the
compatible constraint in tox.ini
- https://review.opendev.org/c/openstack/tempest/+/877713

As new tag is released now so we can switch back to the master
constraint in tox.ini.

Change-Id: Ic91e443ae1948d71fa276be03dcef4576c64df33
1 file changed