Switch to the master constraint in tox.ini

To releas a new tag for Tempest 2025.1, we modified the
compatible constraint in tox.ini
- https://review.opendev.org/c/openstack/tempest/+/945149

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

Change-Id: Ia6cb927af6b0324d961e3c9a3c565c4f326fad39
2 files changed