Added workflow for automerging PRs from LEGO system (#14760)

* Added workflow for automerging PRs from csigs

* Fix mapping

* Change wf name

* Add action only to PRs opened to Localisation branch

.github/workflows/localization-automerge.yml

@@ -0,0 +1,25 @@
+name: 'LEGO automerge'
+
+on:
+  pull_request:
+    types:
+      - opened
+    branches:
+      - Localization
+
+jobs:
+  worker:
+    runs-on: ubuntu-latest
+
+    if: github.actor == 'csigs'
+    steps:
+      - uses: actions/github-script@v3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            github.pulls.merge({
+              owner: context.payload.repository.owner.login,
+              repo: context.payload.repository.name,
+              pull_number: context.payload.pull_request.number,
+              merge_method: 'squash'
+            })