Implement custom OpenTelemetry sampler to filter uninstrumented traces (#8647)

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

beacon_node/network/src/sync/network_context/custody.rs

@@ -6,7 +6,6 @@ use beacon_chain::validator_monitor::timestamp_now;
 use fnv::FnvHashMap;
 use lighthouse_network::PeerId;
 use lighthouse_network::service::api_types::{CustodyId, DataColumnsByRootRequester};
-use lighthouse_tracing::SPAN_OUTGOING_CUSTODY_REQUEST;
 use parking_lot::RwLock;
 use std::collections::HashSet;
 use std::hash::{BuildHasher, RandomState};
@@ -69,7 +68,7 @@ impl<T: BeaconChainTypes> ActiveCustodyRequest<T> {
     ) -> Self {
         let span = debug_span!(
             parent: Span::current(),
-            SPAN_OUTGOING_CUSTODY_REQUEST,
+            "lh_outgoing_custody_request",
             %block_root,
         );
         Self {