Fix duplicate parameters in stale action

[MindTooth]

Noticed this when I tested out Renovate:

{
  "packageFile": ".github/workflows/automate-stale.yml"
  "err": {
    "message": "Failed to parse YAML file",
    "stack": "AggregateError: Failed to parse YAML file\n    at parseSingleYaml (/usr/local/renovate/lib/util/yaml.ts:127:11)\n    at extractWithYAMLParser (/usr/local/renovate/lib/modules/manager/github-actions/extract.ts:190:26)\n    at Object.extractPackageFile (/usr/local/renovate/lib/modules/manager/github-actions/extract.ts:227:8)\n    at extractPackageFile (/usr/local/renovate/lib/modules/manager/index.ts:75:9)\n    at getManagerPackageFiles (/usr/local/renovate/lib/workers/repository/extract/manager-files.ts:58:43)\n    at /usr/local/renovate/lib/workers/repository/extract/index.ts:57:28\n    at async Promise.all (index 0)\n    at extractAllDependencies (/usr/local/renovate/lib/workers/repository/extract/index.ts:54:26)\n    at extract (/usr/local/renovate/lib/workers/repository/process/extract-update.ts:140:28)\n    at extractDependencies (/usr/local/renovate/lib/workers/repository/process/index.ts:155:26)\n    at Object.renovateRepository (/usr/local/renovate/lib/workers/repository/index.ts:71:9)\n    at attributes.repository (/usr/local/renovate/lib/workers/global/index.ts:202:11)\n    at start (/usr/local/renovate/lib/workers/global/index.ts:187:7)\n    at /usr/local/renovate/lib/renovate.ts:18:22"
  }
}

Running then through yamllilnt:

[awanlin]

Hi @MindTooth, thanks for the contribution, we actually just merged a fix for this in #228.