add a github workflow to trigger ent->oss merge on every PR merged (#13072)

* add a github workflow to trigger ent->oss merge on every PR merged

* remove the workflow automation ref to trigger-oss-merge in circle-ci

* remove workflow automation

* revert circle-ci changes

* add actor

* remove cherrypicker

* add condition to avoid running in enterprise

.github/workflows/oss-merge-trigger.yml

@@ -0,0 +1,26 @@
+name: Trigger OSS to Enterprise Merge
+on:
+  pull_request_target:
+    types:
+      - closed
+    branches:
+      - main
+      - 'releases/*.*.x'
+
+jobs:
+  trigger-oss-merge:
+    # run this only on merge events in OSS repo
+    if: ${{ github.event.pull_request.merged && github.repository == 'hashicorp/consul' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Trigger Merge
+        env:
+          GIT_REF: ${{ github.ref_name }}
+          GIT_SHA: ${{ github.sha }}
+          GH_PAT: ${{ secrets.ELEVATED_GITHUB_TOKEN }}
+          GIT_ACTOR: ${{ github.actor }}
+          run: |
+            curl -H "Authorization: token $GH_PAT" \
+              -H 'Accept: application/json' \
+              -d "{\"event_type\": \"oss-merge\", \"client_payload\": {\"git-ref\": \"${GIT_REF}\", \"git-sha\": \"${GIT_SHA}\", \"git-actor\": \"${GIT_ACTOR}\" }}" \
+              "https://api.github.com/repos/hashicorp/consul-enterprise/dispatches"