chore: use cmp in go 1.21

Co-authored-by: H1JK <hell0jack@protonmail.com>

transport/tuic/congestion/minmax_go121.go

@@ -0,0 +1,13 @@
+//go:build go1.21
+
+package congestion
+
+import "cmp"
+
+func Max[T cmp.Ordered](a, b T) T {
+	return max(a, b)
+}
+
+func Min[T cmp.Ordered](a, b T) T {
+	return min(a, b)
+}