Wrap the entire Libp2p object in an Arc

Makes `Clone` calls significantly cheaper as now only the outer Arc is cloned
(the inner ones have been removed). Also wraps uses of Serai in an Arc as we
shouldn't actually need/want multiple caller connection pools.

coordinator/cosign/src/intend.rs

@@ -1,5 +1,5 @@
 use core::future::Future;
-use std::collections::HashMap;
+use std::{sync::Arc, collections::HashMap};
 
 use serai_client::{
   primitives::{SeraiAddress, Amount},
@@ -57,7 +57,7 @@ async fn block_has_events_justifying_a_cosign(
 /// A task to determine which blocks we should intend to cosign.
 pub(crate) struct CosignIntendTask<D: Db> {
   pub(crate) db: D,
-  pub(crate) serai: Serai,
+  pub(crate) serai: Arc<Serai>,
 }
 
 impl<D: Db> ContinuallyRan for CosignIntendTask<D> {

coordinator/cosign/src/lib.rs

@@ -3,7 +3,7 @@
 #![deny(missing_docs)]
 
 use core::{fmt::Debug, future::Future};
-use std::collections::HashMap;
+use std::{sync::Arc, collections::HashMap};
 
 use blake2::{Digest, Blake2s256};
 
@@ -240,7 +240,7 @@ impl<D: Db> Cosigning<D> {
   /// only used once at any given time.
   pub fn spawn<R: RequestNotableCosigns>(
     db: D,
-    serai: Serai,
+    serai: Arc<Serai>,
     request: R,
     tasks_to_run_upon_cosigning: Vec<TaskHandle>,
   ) -> Self {
@@ -334,10 +334,9 @@ impl<D: Db> Cosigning<D> {
     }
   }
 
-  /// Intake a cosign from the Serai network.
+  /// Intake a cosign.
   ///
-  /// - Returns Err(_) if there was an error trying to validate the cosign and it should be retired
-  ///   later.
+  /// - Returns Err(_) if there was an error trying to validate the cosign.
   /// - Returns Ok(true) if the cosign was successfully handled or could not be handled at this
   ///   time.
   /// - Returns Ok(false) if the cosign was invalid.