Drop SLURP job

2025.2 is a non-SLURP release and support upgrade only from 2025.1 .

Change-Id: I53811af8805a326b224818d8765281aa0313078b

.zuul.yaml

@@ -183,12 +183,6 @@
       - ^heat/tests/.*$
       - ^releasenotes/.*$
 
-- job:
-    name: grenade-heat-multinode-skip-level
-    parent: grenade-heat-multinode
-    vars:
-      grenade_from_branch: stable/2024.1
-
 - project:
     queue: heat
     templates:
@@ -202,13 +196,11 @@
     check:
       jobs:
         - grenade-heat-multinode
-        - grenade-heat-multinode-skip-level
         - heat-functional
         - heat-functional-legacy
         - heat-functional-centos-9-stream
     gate:
       jobs:
         - grenade-heat-multinode
-        - grenade-heat-multinode-skip-level
         - heat-functional
         - heat-functional-legacy