fix: build failure due to missing 'using Nethermind.Core'

Author: felix314159

src/Nethermind/Nethermind.Merge.Plugin/EngineRpcModule.Bogota.cs

@@ -5,6 +5,7 @@
 using System.Threading.Tasks;
 using Nethermind.Consensus;
 using Nethermind.Consensus.Producers;
+using Nethermind.Core;
 using Nethermind.Core.Crypto;
 using Nethermind.Core.Specs;
 using Nethermind.JsonRpc;