Update docker.io/rancher/system-upgrade-controller Docker tag to v0.8.1

Signed-off-by: Renovate Bot <tech+renovate@vshn.ch>

Author: vshn-renovate

class/defaults.yml

@@ -4,7 +4,7 @@ parameters:
       system_upgrade_controller:
         registry: docker.io
         repository: rancher/system-upgrade-controller
-        tag: v0.6.2
+        tag: v0.8.1
     plans_only: false
     controller_threads: "2"
     affinity: {}