renovate config warnings

[sogladev]

https://github.com/sogladev/home-media-server/actions/runs/12757954991/job/35559249237

 WARN: Found renovate config warnings (repository=sogladev/home-media-server)
       "warnings": [
         {
           "topic": "Configuration Error",
           "message": "The \"repositories\" option is a global option reserved only for Renovate's global configuration and cannot be configured within a repository's config file."
         }
       ]

• repositories
• onboarding renovate: remove onboarding config #26