refactor: Stop reporting to Sentry Facebook multi-webhook error (no-changelog) (#7743)

https://n8nio.sentry.io/issues/4640072705

packages/nodes-base/nodes/Facebook/FacebookTrigger.node.ts

@@ -195,6 +195,7 @@ export class FacebookTrigger implements INodeType {
 					throw new NodeOperationError(
 						this.getNode(),
 						`The Facebook App ID ${appId} already has a webhook subscription. Delete it or use another App before executing the trigger. Due to Facebook API limitations, you can have just one trigger per App.`,
+						{ severity: 'warning' },
 					);
 				}