utils: replace defer, ContextGuard, DetachableTask with guarden crate (#2163)

easytier/src/gateway/kcp_proxy.rs

@@ -7,6 +7,7 @@ use std::{
 use anyhow::Context;
 use bytes::Bytes;
 use dashmap::DashMap;
+use guarden::defer;
 use kcp_sys::{
     endpoint::{ConnId, KcpEndpoint, KcpPacketReceiver},
     ffi_safe::KcpConfig,
@@ -359,7 +360,7 @@ impl KcpProxyDst {
                 transport_type: TcpProxyEntryTransportType::Kcp.into(),
             },
         );
-        crate::defer! {
+        defer! {
             proxy_entries.remove(&conn_id);
             if proxy_entries.capacity() - proxy_entries.len() > 16 {
                 proxy_entries.shrink_to_fit();

easytier/src/gateway/quic_proxy.rs

@@ -24,6 +24,7 @@ use bytes::{BufMut, Bytes, BytesMut};
 use dashmap::DashMap;
 use derivative::Derivative;
 use derive_more::{Constructor, Deref, DerefMut, From, Into};
+use guarden::defer;
 use prost::Message;
 use quinn::udp::{EcnCodepoint, RecvMeta, Transmit};
 use quinn::{
@@ -662,7 +663,7 @@ impl QuicStreamReceiver {
                 transport_type: TcpProxyEntryTransportType::Quic.into(),
             },
         );
-        crate::defer! {
+        defer! {
             proxy_entries.remove(&handle);
             if proxy_entries.capacity() - proxy_entries.len() > 16 {
                 proxy_entries.shrink_to_fit();