Remove redundant subscribe_all_data_column_subnets field from network (#8259)

Addresses this comment: https://github.com/sigp/lighthouse/pull/8254#discussion_r2447998786

We're currently using `subscribe_all_data_column_subnets` here to subscribe to all subnets
522bd9e9c6/beacon_node/lighthouse_network/src/types/topics.rs (L82-L92)

But its unnecessary because the else path also works for supernode (uses `sampling_subnets` instead)

The big diffs will disappear once #8254 is merged.


  


Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>

beacon_node/src/config.rs

@@ -114,7 +114,6 @@ pub fn get_config<E: EthSpec>(
     let is_semi_supernode = parse_flag(cli_args, "semi-supernode");
 
     client_config.chain.node_custody_type = if is_supernode {
-        client_config.network.subscribe_all_data_column_subnets = true;
         NodeCustodyType::Supernode
     } else if is_semi_supernode {
         NodeCustodyType::SemiSupernode