message: delete the pr environment when the branch is either closed or merged.
diff: @@ -154,6 +154,7 @@ async function processWebhook (rabbitMsg: RabbitMQMsg, channelWrapperWebhooks: C
  await handle(gitlabPullRequestUpdated, webhook, project, `${webhooktype}:${event}:${body.object_attributes.action}`)
  break;
  + case 'merge':
  case 'close':
  await handle(gitlabPullRequestClosed, webhook, project, `${webhooktype}:${event}:${body.object_attributes.action}`)
  break;
  