use the slices package to simply QUIC version comparisons (#5130)

No functional change expected.

connection.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"reflect"
+	"slices"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -1278,8 +1279,7 @@ func (s *connection) handleVersionNegotiationPacket(p receivedPacket) {
 		return
 	}
 
-	for _, v := range supportedVersions {
-		if v == s.version {
+	if slices.Contains(supportedVersions, s.version) {
 		if s.tracer != nil && s.tracer.DroppedPacket != nil {
 			s.tracer.DroppedPacket(logging.PacketTypeVersionNegotiation, protocol.InvalidPacketNumber, p.Size(), logging.PacketDropUnexpectedVersion)
 		}
@@ -1287,7 +1287,6 @@ func (s *connection) handleVersionNegotiationPacket(p receivedPacket) {
 		// This might be a packet sent by an attacker, or it was corrupted.
 		return
 	}
-	}
 
 	s.logger.Infof("Received a Version Negotiation packet. Supported Versions: %s", supportedVersions)
 	if s.tracer != nil && s.tracer.ReceivedVersionNegotiationPacket != nil {

internal/protocol/version.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math"
 	mrand "math/rand/v2"
+	"slices"
 	"sync"
 )
 
@@ -64,12 +65,7 @@ func (vn Version) toGQUICVersion() int {
 
 // IsSupportedVersion returns true if the server supports this version
 func IsSupportedVersion(supported []Version, v Version) bool {
-	for _, t := range supported {
-		if t == v {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(supported, v)
 }
 
 // ChooseSupportedVersion finds the best version in the overlap of ours and theirs
@@ -78,12 +74,10 @@ func IsSupportedVersion(supported []Version, v Version) bool {
 // The bool returned indicates if a matching version was found.
 func ChooseSupportedVersion(ours, theirs []Version) (Version, bool) {
 	for _, ourVer := range ours {
-		for _, theirVer := range theirs {
-			if ourVer == theirVer {
+		if slices.Contains(theirs, ourVer) {
 			return ourVer, true
 		}
 	}
-	}
 	return 0, false
 }