perf: simplify method signatures and reduce clone across multiple files (#1663)

easytier/src/tunnel/udp.rs

@@ -798,7 +798,7 @@ impl UdpTunnelConnector {
     }
 
     async fn connect_with_default_bind(
-        &mut self,
+        &self,
         addr: SocketAddr,
     ) -> Result<Box<dyn Tunnel>, super::TunnelError> {
         let socket = if addr.is_ipv4() {
@@ -811,7 +811,7 @@ impl UdpTunnelConnector {
     }
 
     async fn connect_with_custom_bind(
-        &mut self,
+        &self,
         addr: SocketAddr,
     ) -> Result<Box<dyn Tunnel>, super::TunnelError> {
         let futures = FuturesUnordered::new();