Update renovate.json

General MR

Summary

Remove dependencyDashboardHeader from renovate.json. This is now a variable populated from the renovate.yaml pipeline template.

Relevant logs/screenshots

N/A

Linked Issue

issue

Upgrade Notices

N/A

renovate.json

@@ -2,7 +2,6 @@
   "baseBranches": ["main"],
   "configWarningReuseIssue": false,
   "dependencyDashboard": "true",
-  "dependencyDashboardHeader": "- [ ] Follow steps in [package update docs](./docs/PACKAGE_UPDATES.md) to upgrade the package.",
   "dependencyDashboardTitle": "Renovate: Upgrade Mattermost Package Dependencies",
   "draftPR": true,
   "enabledManagers": ["regex", "helmv3"],