cluster: remove unused variables on scan option factories

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/cluster/cluster_scan_options.go

@@ -27,7 +27,7 @@ type ScanOptions struct {
 // the DNS resolver to get PublicAddresses of nodes.
 // Default is true
 func ResolvePublicAddresses(resolve bool) ScanOption {
-	return func(m *Cluster, opt *ScanOptions) error {
+	return func(_ *Cluster, opt *ScanOptions) error {
 		opt.DontResolvePublicAddresses = !resolve
 		return nil
 	}
@@ -36,7 +36,7 @@ func ResolvePublicAddresses(resolve bool) ScanOption {
 // WithLookuper specifies what resolver.Lookuper to use to
 // find public addresses
 func WithLookuper(h resolver.Lookuper) ScanOption {
-	return func(m *Cluster, opt *ScanOptions) error {
+	return func(m *Cluster, _ *ScanOptions) error {
 		if h == nil {
 			return fs.ErrInvalid
 		}
@@ -49,7 +49,7 @@ func WithLookuper(h resolver.Lookuper) ScanOption {
 // public addresses. if nil is passed, the [net.Resolver] will be used.
 // The default is using Cloudflare's 1.1.1.1.
 func WithResolver(h resolver.Resolver) ScanOption {
-	return func(m *Cluster, opt *ScanOptions) error {
+	return func(m *Cluster, _ *ScanOptions) error {
 		if h == nil {
 			h = resolver.SystemResolver(true)
 		}