fix(targets): accept both DnsFailure and Unreachable in macOS DNS test (#5138)

On macOS with DNS interception services, .invalid TLD domains resolve
to an interception address (e.g. 198.18.16.173) instead of failing DNS
resolution. The health probe then classifies the error as Unreachable
rather than DnsFailure. Accept both outcomes since both are correct
non-reachable error classifications.

crates/targets/src/target/webhook.rs

@@ -936,7 +936,13 @@ mod tests {
         let health = probe_health_url(&client, &url).await;
 
         assert_eq!(health.state, TargetHealthState::Error);
-        assert_eq!(health.reason, TargetHealthReason::DnsFailure);
+        // On systems with DNS interception (common on macOS), `.invalid` may resolve
+        // to an interception address, producing `Unreachable` instead of `DnsFailure`.
+        assert!(
+            matches!(health.reason, TargetHealthReason::DnsFailure | TargetHealthReason::Unreachable),
+            "expected DnsFailure or Unreachable, got {:?}",
+            health.reason
+        );
     }
 
     #[tokio::test(start_paused = true)]