Use explicit repository list instead of autodiscover

Gitea's /api/v1/user/repos (which Renovate calls during autodiscover)
returns repos where the user is owner or org member, but NOT
collaborator-only repos. Our renovate service account has write
collaborator access on Micha/homelab-infra but no own/org repos,
so autodiscover yielded an empty list.

Switching to explicit "repositories": ["Micha/homelab-infra"] is
the pragmatic fix for a homelab with one repo to scan; avoids
having to create an org just for one service account.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

renovate.json

@@ -11,8 +11,8 @@
   "gitAuthor": "Renovate Bot <renovate@kaleschke.info>",
   "onboarding": false,
   "requireConfig": "optional",
-  "autodiscover": true,
-  "autodiscoverFilter": ["Micha/*"],
+  "autodiscover": false,
+  "repositories": ["Micha/homelab-infra"],
   "dependencyDashboardTitle": "Renovate Dependency Dashboard",
   "prHourlyLimit": 0,
   "prConcurrentLimit": 5,