Release Magnum 9.4.1 for stable/train

After the 9.4.0 release there has been four very
small bugfixes. For example the [1] change is
required for Cinder CSI to even work with the
default k8s version v1.15 in Train.

[1] https://review.opendev.org/c/openstack/magnum/+/750058

Change-Id: I2dd929725e16317749c5c9f6022967a45f13b2a9

deliverables/train/magnum.yaml

@@ -54,6 +54,10 @@ releases:
     projects:
       - repo: openstack/magnum
         hash: 368241fda7fbe146f824193b1e0b39b73c226f87
+  - version: 9.4.1
+    projects:
+      - repo: openstack/magnum
+        hash: 528ec941da294b454221170e1919b7dc18d10e86
 branches:
   - name: stable/train
     location: 9.0.0.0rc1