remove custom contains funcs for slices.Contains (#2015)

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

cmd/headscale/cli/nodes.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"net/netip"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -617,14 +618,14 @@ func nodesToPtables(
 		forcedTags = strings.TrimLeft(forcedTags, ",")
 		var invalidTags string
 		for _, tag := range node.GetInvalidTags() {
-			if !contains(node.GetForcedTags(), tag) {
+			if !slices.Contains(node.GetForcedTags(), tag) {
 				invalidTags += "," + pterm.LightRed(tag)
 			}
 		}
 		invalidTags = strings.TrimLeft(invalidTags, ",")
 		var validTags string
 		for _, tag := range node.GetValidTags() {
-			if !contains(node.GetForcedTags(), tag) {
+			if !slices.Contains(node.GetForcedTags(), tag) {
 				validTags += "," + pterm.LightGreen(tag)
 			}
 		}

cmd/headscale/cli/utils.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
-	"reflect"
 
 	"github.com/rs/zerolog/log"
 	"google.golang.org/grpc"
@@ -197,13 +196,3 @@ func (t tokenAuth) GetRequestMetadata(
 func (tokenAuth) RequireTransportSecurity() bool {
 	return true
 }
-
-func contains[T string](ts []T, t T) bool {
-	for _, v := range ts {
-		if reflect.DeepEqual(v, t) {
-			return true
-		}
-	}
-
-	return false
-}