fn filter_duplicate_gateways(
gateways: &BTreeMap<PeerId, Vec<LightningGatewayAnnouncement>>,
) -> Vec<LightningGatewayAnnouncement>Expand description
Filter out duplicate gateways. This is necessary because different guardians
may have different TTLs for the same gateway, so two
LightningGatewayAnnouncements representing the same gateway registration
may not be equal.