fix: Treat certifications like other in-memory states to keep around when pruning. Reverts the revert of async hashing.

rs/consensus/BUILD.bazel

@@ -77,7 +77,6 @@ DEV_DEPENDENCIES = [
     "@crate_index//:slog-term",
     "@crate_index//:strum",
     "@crate_index//:tempfile",
-    "@crate_index//:tokio",
 ]
 
 NONMALICIOUS_DEPENDENCIES = [
@@ -198,5 +197,6 @@ rust_ic_bench(
         "//rs/types/types",
         "@crate_index//:criterion",
         "@crate_index//:tempfile",
+        "@crate_index//:tokio",
     ],
 )

rs/consensus/benches/validate_payload.rs

@@ -104,6 +104,7 @@ where
             &StateManagerConfig::new(tmpdir.path().to_path_buf()),
             None,
             ic_types::malicious_flags::MaliciousFlags::default(),
+            tokio::sync::watch::channel(ic_types::Height::from(0)).0,
         );
         setup_ingress_state(now, &mut state_manager);
         let state_manager = Arc::new(state_manager);

rs/consensus/certification/BUILD.bazel

@@ -17,7 +17,6 @@ DEPENDENCIES = [
     "//rs/types/types",
     "@crate_index//:prometheus",
     "@crate_index//:slog",
-    "@crate_index//:tokio",
 ]
 
 DEV_DEPENDENCIES = [

rs/consensus/certification/Cargo.toml

@@ -20,7 +20,6 @@ ic-replicated-state = { path = "../../replicated_state" }
 ic-types = { path = "../../types/types" }
 prometheus = { workspace = true }
 slog = { workspace = true }
-tokio = { workspace = true }
 
 [dev-dependencies]
 assert_matches = { workspace = true }