Update Artifact trait to comply with 'object safety'

Author: jpraynaud

mithril-aggregator/src/artifact_builder/dummy_artifact.rs

@@ -22,6 +22,7 @@ impl DummyArtifact {
     }
 }
 
+#[typetag::serde]
 impl Artifact for DummyArtifact {}
 
 /// A [DummyArtifact] builder

mithril-aggregator/src/artifact_builder/mithril_stake_distribution.rs

@@ -24,6 +24,7 @@ impl MithrilStakeDistribution {
     }
 }
 
+#[typetag::serde]
 impl Artifact for MithrilStakeDistribution {}
 
 /// A [MithrilStakeDistributionArtifact] builder

mithril-common/src/signable_builder/interface.rs

@@ -1,5 +1,4 @@
 use async_trait::async_trait;
-use serde::{de::DeserializeOwned, Serialize};
 use std::fmt::Debug;
 
 use crate::{entities::ProtocolMessage, StdResult};
@@ -14,7 +13,8 @@ pub trait Signable: Send + Sync {
 }
 
 /// Artifact is a trait for types that represent signed artifacts
-pub trait Artifact: Serialize + DeserializeOwned + PartialEq + Debug + Send + Sync {}
+#[typetag::serde(tag = "type")]
+pub trait Artifact: Debug + Send + Sync {}
 
 /// SignableBuilder is trait for building a signable for a beacon
 #[async_trait]