Replace maps.Clear with builtin clear; fix appendAssign in test

client/firewall/uspfilter/filter.go

@@ -20,7 +20,6 @@ import (
 	"github.com/google/uuid"
 	"github.com/hashicorp/go-multierror"
 	log "github.com/sirupsen/logrus"
-	"golang.org/x/exp/maps"
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
@@ -675,10 +674,10 @@ func (m *Manager) Flush() error { return nil }
 // resetState clears all firewall rules and closes connection trackers.
 // Must be called with m.mutex held.
 func (m *Manager) resetState() {
-	maps.Clear(m.outgoingRules)
-	maps.Clear(m.incomingDenyRules)
-	maps.Clear(m.incomingRules)
-	maps.Clear(m.routeRulesMap)
+	clear(m.outgoingRules)
+	clear(m.incomingDenyRules)
+	clear(m.incomingRules)
+	clear(m.routeRulesMap)
 	m.routeRules = m.routeRules[:0]
 	m.udpHookOut.Store(nil)
 	m.tcpHookOut.Store(nil)

client/firewall/uspfilter/forwarder/forwarder_test.go

@@ -67,7 +67,8 @@ func TestParseICMPv6_SingleExtension(t *testing.T) {
 	src := netip.MustParseAddr("fd00::1")
 	dst := netip.MustParseAddr("fd00::2")
 	hbh := extHdr(t, uint8(header.ICMPv6ProtocolNumber), 8)
-	payload := append(hbh, echoRequest()...)
+	payload := append([]byte{}, hbh...)
+	payload = append(payload, echoRequest()...)
 	pkt := makeIPv6(t, src, dst, uint8(header.IPv6HopByHopOptionsExtHdrIdentifier), payload)
 
 	off, icmpLen, _, _, ok := parseICMPv6(pkt)

client/internal/dns/server.go

@@ -410,7 +410,7 @@ func (s *DefaultServer) Stop() {
 		log.Errorf("failed to disable DNS: %v", err)
 	}
 
-	maps.Clear(s.extraDomains)
+	clear(s.extraDomains)
 }
 
 func (s *DefaultServer) disableDNS() (retErr error) {