fix: fix linting issue on my computer

cmd/headscale/cli/utils.go

@@ -566,7 +566,7 @@ func GetFileMode(key string) fs.FileMode {
 	return fs.FileMode(mode)
 }
 
-func contains(ts []T, t T) bool {
+func contains[T string](ts []T, t T) bool {
 	for _, v := range ts {
 		if reflect.DeepEqual(v, t) {
 			return true