[stable-only] Drop skip-level jobs in the CI

These jobs are currently broken due to a partial migration to um/2023.1.
Because the older branch is now in unmantained mode, these jobs are
not longer executed in this stable branch.

Related-Bug: #2089522
Change-Id: Id17831323822b4c2aa89442c8bfc6b089809b9b8

zuul.d/grenade.yaml

@@ -381,35 +381,3 @@
             PHYSICAL_NETWORK: public
             ENABLE_CHASSIS_AS_GW: false
             OVN_DBS_LOG_LEVEL: dbg
-
-- job:
-    name: neutron-ovs-grenade-multinode-skip-level
-    parent: neutron-ovs-grenade-multinode
-    description: |
-      Grenade job that skips a release, validating that deployers can skip
-      specific releases as prescribed by our process.
-    vars:
-      # Move this forward when master changes to a new skip-level-allowed
-      # target release. Right now, this is Antelope (2023.1) because master is
-      # Caracal (2024.1).
-      # When master is E (2025.1), this should become Caracal (2024.1),
-      # and so forth.
-      grenade_from_branch: stable/2023.1
-      grenade_localrc:
-        NOVA_ENABLE_UPGRADE_WORKAROUND: True
-
-- job:
-    name: neutron-ovn-grenade-multinode-skip-level
-    parent: neutron-ovn-grenade-multinode
-    description: |
-      Grenade job that skips a release, validating that deployers can skip
-      specific releases as prescribed by our process.
-    vars:
-      # Move this forward when master changes to a new skip-level-allowed
-      # target release. Right now, this is Antelope (2023.1) because master is
-      # Caracal (2024.1).
-      # When master is E (2025.1), this should become Caracal (2024.1),
-      # and so forth.
-      grenade_from_branch: stable/2023.1
-      grenade_localrc:
-        NOVA_ENABLE_UPGRADE_WORKAROUND: True

zuul.d/job-templates.yaml

@@ -109,20 +109,3 @@
         - neutron-tempest-plugin-linuxbridge-2024-1
     experimental:
       jobs: *neutron-periodic-jobs
-
-- project-template:
-    name: neutron-skip-level-jobs
-    # During a SLURP release, these jobs are executed in the check queue,
-    # otherwise periodic/experimental. SLURP releases are 2024.1, 2025.1, etc.
-    check:
-      jobs:
-        - neutron-ovs-grenade-multinode-skip-level
-        - neutron-ovn-grenade-multinode-skip-level
-    #periodic:
-    #  jobs:
-    #    - neutron-ovs-grenade-multinode-skip-level
-    #    - neutron-ovn-grenade-multinode-skip-level
-    #experimental:
-    #  jobs:
-    #    - neutron-ovs-grenade-multinode-skip-level
-    #    - neutron-ovn-grenade-multinode-skip-level

zuul.d/project.yaml

@@ -15,7 +15,6 @@
       - neutron-experimental-jobs
       - neutron-periodic-jobs
       - neutron-tox-override-jobs
-      - neutron-skip-level-jobs
     check:
       jobs:
         - neutron-functional-with-uwsgi