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/config.rs

@@ -94,9 +94,6 @@ pub struct Config {
     /// Attempt to construct external port mappings with UPnP.
     pub upnp_enabled: bool,
 
-    /// Subscribe to all data column subnets for the duration of the runtime.
-    pub subscribe_all_data_column_subnets: bool,
-
     /// Subscribe to all subnets for the duration of the runtime.
     pub subscribe_all_subnets: bool,
 
@@ -355,7 +352,6 @@ impl Default for Config {
             upnp_enabled: true,
             network_load: 3,
             private: false,
-            subscribe_all_data_column_subnets: false,
             subscribe_all_subnets: false,
             import_all_attestations: false,
             shutdown_after_sync: false,