refactor(core): remove hotpath profiling (#2394)

hotpath adds noticeable overhead on hot paths, so remove the optional
profiling integration while keeping direct quanta::Instant timing.

easytier/src/peers/relay_peer_map.rs

@@ -1,8 +1,8 @@
 use std::sync::Arc;
 
 use dashmap::DashMap;
-use hotpath::instant::Instant;
 use prost::Message;
+use quanta::Instant;
 use snow::params::NoiseParams;
 use tokio::sync::{Mutex, OwnedMutexGuard, oneshot};
 use tokio::time::{Duration, timeout};