Fix job event webhook documentation inconsistency with its actual request body

doc/user/project/integrations/webhooks.md

@@ -1181,20 +1181,20 @@ X-Gitlab-Event: Job Hook
 ```json
 {
-  "object_kind": "job",
+  "object_kind": "build",
   "ref": "gitlab-script-trigger",
   "tag": false,
   "before_sha": "2293ada6b400935a1378653304eaf6221e0fdb8f",
   "sha": "2293ada6b400935a1378653304eaf6221e0fdb8f",
-  "job_id": 1977,
-  "job_name": "test",
-  "job_stage": "test",
-  "job_status": "created",
-  "job_started_at": null,
-  "job_finished_at": null,
-  "job_duration": null,
-  "job_allow_failure": false,
-  "job_failure_reason": "script_failure",
+  "build_id": 1977,
+  "build_name": "test",
+  "build_stage": "test",
+  "build_status": "created",
+  "build_started_at": null,
+  "build_finished_at": null,
+  "build_duration": null,
+  "build_allow_failure": false,
+  "build_failure_reason": "script_failure",
   "project_id": 380,
   "project_name": "gitlab-org/gitlab-test",
   "user": {