Remove unused code

Author: lixmal

client/firewall/uspfilter/nat.go

@@ -206,19 +206,6 @@ func (t *portNATTracker) shouldApplyNAT(srcIP, dstIP netip.Addr, dstPort uint16)
 	return true
 }
 
-// cleanupConnection removes a NAT connection.
-func (t *portNATTracker) cleanupConnection(srcIP, dstIP netip.Addr, srcPort uint16) {
-	t.mutex.Lock()
-	defer t.mutex.Unlock()
-
-	for key := range t.connections {
-		if key.SrcIP == srcIP && key.DstIP == dstIP && key.SrcPort == srcPort {
-			delete(t.connections, key)
-			return
-		}
-	}
-}
-
 // newBiDNATMap creates a new bidirectional DNAT mapping structure.
 func newBiDNATMap() *biDNATMap {
 	return &biDNATMap{