[mistral] Create 2025.1 branch for client and non-client libs

This creates the stable/2025.1 branch for all client and non-client
libraries now that we are past the library freeze.

If the team wants to wait for a specific patch to make it to the
library (for example if the gate of the deliverable is broken and
needs to be fixed before branching), then someone from the team can
-1 the patch to have it held, or update that patch with a different
commit SHA. If there is nothing to wait for, then please do respond
on this patch with +1.

In any case, if the patch got no response, then this will be merged
after Thursday, March 6th.

Change-Id: I70521291312e241d85e73e290c9fd712d61e0107

deliverables/epoxy/mistral-extra.yaml

@@ -15,3 +15,6 @@ releases:
     projects:
       - repo: openstack/mistral-extra
         hash: 54084b0d2e2cb1c9e3bd8f305c9ced9fd83199a1
+branches:
+  - name: stable/2025.1
+    location: 15.0.0

deliverables/epoxy/mistral-lib.yaml

@@ -23,3 +23,6 @@ releases:
     projects:
       - repo: openstack/mistral-lib
         hash: a3560015ea64e4d3bb8786df174e748d92d4d9d9
+branches:
+  - name: stable/2025.1
+    location: 3.3.1

deliverables/epoxy/python-mistralclient.yaml

@@ -11,3 +11,6 @@ releases:
     projects:
       - repo: openstack/python-mistralclient
         hash: c055eb159f7738fcac5831425f6ddc3fb2bfa320
+branches:
+  - name: stable/2025.1
+    location: 5.4.0