Renovate configuration @only-patch broken

[pmalek]

Problem statement

Our renovate config for @only-patch updates is invalid and results in build errors:

DEBUG: Datasource unknown error
{
  "datasource": "docker"
  "packageName": "istio/istioctl@only-patch"
  "err": {
    "message": "page-not-found",
    "stack": "Error: page-not-found\n    at getAuthHeaders (/usr/local/renovate/lib/modules/datasource/docker/common.ts:75:13)\n    at processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at DockerDatasource.getDockerApiTags (/usr/local/renovate/lib/modules/datasource/docker/index.ts:658:21)\n    at DockerDatasource.getTags (/usr/local/renovate/lib/modules/datasource/docker/index.ts:725:16)\n    at /usr/local/renovate/lib/util/cache/package/decorator.ts:134:20\n    at DockerDatasource.getReleases (/usr/local/renovate/lib/modules/datasource/docker/index.ts:1081:36)\n    at /usr/local/renovate/lib/util/cache/package/decorator.ts:134:20\n    at getRegistryReleases (/usr/local/renovate/lib/modules/datasource/index.ts:85:15)\n    at fetchReleases (/usr/local/renovate/lib/modules/datasource/index.ts:318:15)"
  }
}

DEBUG: Failed to look up docker package istio/istioctl@only-patch
{
  "dependency": "istio/istioctl@only-patch"
  "packageFile": ".github/test_dependencies.yaml"
}

DEBUG: Failed to look up docker package istio/istioctl@only-patch
{
  "dependency": "istio/istioctl@only-patch"
  "packageFile": ".github/test_dependencies.yaml"
}

DEBUG: Failed to look up docker package istio/istioctl@only-patch
{
  "dependency": "istio/istioctl@only-patch"
  "packageFile": ".github/test_dependencies.yaml"
}

https://developer.mend.io/github/Kong/kubernetes-ingress-controller/-/job/9658a562-630c-4025-bdb0-0176a5c4c621

One can also observe the effects of this: https://hub.docker.com/r/istio/istioctl/tags?name=1.22 do contain newer versions than 1.22.3 (1.22.6 as of today) which is currently defined in test_dependencies.yaml.

Acceptance criteria

• Renovate config does not produce errors related to @only-patch and properly produces PRs related to dependencies using these markers.