1794765cc6
TestListenService needs to setup state (capabilities, advertised routes, ACL tags, etc.). It is imperative that this state propagates to all nodes in the test tailnet before proceeding with the test. To achieve this, TestListenService currently polls each node's local backend in a loop. Using local.Client.WatchIPNBus improves the situation by blocking until a new netmap comes in. Fixes tailscale/corp#36244 Signed-off-by: Harry Harpham <harry@tailscale.com>