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/lighthouse_network/src/service/mod.rs

@@ -199,7 +199,7 @@ impl<E: EthSpec> Network<E> {
             local_keypair.clone(),
             &config,
             &ctx.enr_fork_id,
-            Some(advertised_cgc),
+            advertised_cgc,
             next_fork_digest,
             &ctx.chain_spec,
         )?;