migrate renovate config to gitea

.github/renovate.json

@@ -1,30 +0,0 @@
-{
-  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
-  "extends": [
-    "config:recommended",
-    ":disableDependencyDashboard"
-  ],
-  "assignees": [
-    "valentineus"
-  ],
-  "labels": [
-    "dependencies",
-    "automated"
-  ],
-  "packageRules": [
-    {
-      "groupName": "all digest updates",
-      "groupSlug": "all-digest",
-      "matchUpdateTypes": [
-        "minor",
-        "patch",
-        "pin",
-        "digest"
-      ],
-      "matchPackageNames": [
-        "*"
-      ],
-      "automerge": true
-    }
-  ]
-}