Add Tempest gate job for stable/2026.1

Now we have stable/2026.1 branch ready for devstack
and so does for all service projects.

This commit adds the Tempest testing for stable/2026.1
by adding new jobs running on stable/2026.1 version of
openstack.

Change-Id: I801632d437bbaad49168df15b4763887e35af408
Signed-off-by: Ghanshyam Maan <gmaan.os14@gmail.com>
2 files changed