Disable an unreliable test on macOS (#2997)

We keep the test active on other platforms,
because it passes on them.

Co-authored-by: Conrado Gouvea <conrado@zfnd.org>

zebra-network/src/peer_set/initialize/tests/vectors.rs

@@ -949,6 +949,10 @@ async fn listener_peer_limit_default_handshake_error() {
 
 /// Test the listener with the default inbound peer limit,
 /// and a handshaker that returns success then disconnects the peer.
+///
+/// TODO: tweak the crawler timeouts and rate-limits so we get over the actual limit on macOS
+///       (currently, getting over the limit can take 30 seconds or more)
+#[cfg(not(target_os = "macos"))]
 #[tokio::test]
 async fn listener_peer_limit_default_handshake_ok_then_drop() {
     zebra_test::init();