renovate: remove orphan } left by previous cleanup PR (#85)

The previous PR deleted the umami packageRule but left a stray closing
brace after it, which broke the embedded config.json. ArgoCD applied
the manifest as a string (it's a ConfigMap; k8s doesn't validate the
JSON inside data), so the live ConfigMap also has the invalid JSON --
next Renovate run would fail to parse the config.

Removing the orphan brace restores valid JSON. Verified `json.loads`
parses to 3 customManagers + 7 packageRules.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

admin-system/renovate.yaml

@@ -149,7 +149,6 @@ data:
             "linuxserver/sonarr"
           ],
           "enabled": false
-        },
         }
       ],
       "labels": ["renovate"]