Disable upgrade-minor verification for 5-scos-next stream (#82190)

The upgrade-minor job is configured with upgradeFrom: PreviousMinor,
but for version 5.0.0 (minor=0) there is no previous minor release
to upgrade from. This causes the job to stay Pending indefinitely,
which prevents the release controller from making an accept/reject
decision — leaving releases stuck in Ready state.

Disable the job until 5.1 becomes available. The job definition is
preserved so it can be re-enabled by removing the disabled flag.

Author: pskrbasu

core-services/release-controller/_releases/release-okd-scos-5.y-next.json

@@ -17,6 +17,7 @@
       "maxRetries": 2
     },
     "upgrade-minor":{
+      "disabled":true,
       "upgrade":true,
       "upgradeFrom": "PreviousMinor",
       "prowJob": {