cmd/devp2p: submit Route53 changes in batches (#20524)

This change works around the 32k RDATA character limit per change
request and fixes several issues in the deployer which prevented it from
working for our production trees.

cmd/devp2p/dnscmd.go

@@ -96,6 +96,11 @@ var (
 	}
 )
 
+const (
+	rootTTL     = 1
+	treeNodeTTL = 2147483647
+)
+
 // dnsSync performs dnsSyncCommand.
 func dnsSync(ctx *cli.Context) error {
 	var (