fix: Use right automerge field from config (#12145)

Co-authored-by: Rhys Arkins <rhys@arkins.net>

lib/workers/pr/__snapshots__/index.spec.ts.snap

@@ -95,7 +95,7 @@ Array [
       "azureWorkItemId": 0,
       "bbUseDefaultReviewers": true,
       "gitLabIgnoreApprovals": false,
-      "usePlatformAutomerge": false,
+      "usePlatformAutomerge": true,
     },
     "prBody": "This PR contains the following updates:\\n\\n| Package | Type | Update | Change |\\n|---|---|---|---|\\n| [dummy](https://dummy.com) ([source](https://github.com/renovateapp/dummy), [changelog](https://github.com/renovateapp/dummy/changelog.md)) | devDependencies | minor | \`1.0.0\` -> \`1.1.0\` |\\n\\n---\\n\\n### Release Notes\\n\\n<details>\\n<summary>renovateapp/dummy</summary>\\n\\n### [\`v1.1.0\`](https://github.com/renovateapp/dummy/compare/v1.0.0...v1.1.0)\\n\\n[Compare Source](https://github.com/renovateapp/dummy/compare/v1.0.0...v1.1.0)\\n\\n</details>\\n\\n---\\n\\n### Configuration\\n\\n📅 **Schedule**: \\"before 5am\\" (UTC).\\n\\n🚦 **Automerge**: Enabled.\\n\\n♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.\\n\\n🔕 **Ignore**: Close this PR and you won't be reminded about this update again.\\n\\n---\\n\\n - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box.\\n\\n---\\n\\nThis PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).",
     "prTitle": "Update dependency dummy to v1.1.0",
@@ -115,7 +115,7 @@ Array [
       "azureWorkItemId": 0,
       "bbUseDefaultReviewers": true,
       "gitLabIgnoreApprovals": false,
-      "usePlatformAutomerge": false,
+      "usePlatformAutomerge": true,
     },
     "prBody": "This PR contains the following updates:\\n\\n| Package | Type | Update | Change |\\n|---|---|---|---|\\n| [gitlabdummy](https://dummy.com) ([source](https://gitlab.com/renovateapp/gitlabdummy), [changelog](https://gitlab.com/renovateapp/gitlabdummy/changelog.md)) | devDependencies | minor | \`1.0.0\` -> \`1.1.0\` |\\n\\n---\\n\\n### Configuration\\n\\n📅 **Schedule**: \\"before 5am\\" (UTC).\\n\\n🚦 **Automerge**: Enabled.\\n\\n♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.\\n\\n🔕 **Ignore**: Close this PR and you won't be reminded about this update again.\\n\\n---\\n\\n - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box.\\n\\n---\\n\\nThis PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).",
     "prTitle": "Update dependency dummy to v1.1.0",

lib/workers/pr/index.ts

@@ -119,7 +119,7 @@ export function getPlatformPrOptions(
   const usePlatformAutomerge = Boolean(
     config.automerge &&
       config.automergeType === 'pr' &&
-      config.usePlatformAutomerge
+      config.platformAutomerge
   );
 
   return {