[Backport 8.15] Add support for auto-merge (#2339)

* Add support for auto-merge

* Fix bad request-converter version

* Switch back to pull_request

pull_request_target is the wrong trigger for this action

(cherry picked from commit 4b8969cc78)

Co-authored-by: Josh Mock <joshua.mock@elastic.co>

.github/workflows/auto-merge.yml

@@ -0,0 +1,17 @@
+name: Automerge
+
+on:
+  pull_request_review:
+    types:
+      - submitted
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: reitermarkus/automerge@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          merge-method: squash
+          do-not-merge-labels: never-merge
+          pull-request-author-associations: OWNER

.github/workflows/nodejs.yml

@@ -2,7 +2,7 @@
 name: Node CI
 
 on:
-  pull_request_target: {}
+  pull_request: {}
 
 jobs:
   paths-filter:

package.json

@@ -50,7 +50,7 @@
     "node": ">=18"
   },
   "devDependencies": {
-    "@elastic/request-converter": "^8.16.0",
+    "@elastic/request-converter": "^8.15.2",
     "@sinonjs/fake-timers": "github:sinonjs/fake-timers#0bfffc1",
     "@types/debug": "^4.1.7",
     "@types/ms": "^0.7.31",