fix: throwable sign

Author: ieow

Sources/MPCEthereumProvider/MPCEthereumProvider.swift

@@ -15,7 +15,7 @@ import curveSecp256k1
 
 
 public protocol EvmSigner {
-    func sign( message: Data ) -> Data
+    func sign( message: Data ) throws -> Data
     var publicKey : Data { get }
 }
 

Tests/Web3SwiftMpcProviderTests/signer.swift

@@ -46,11 +46,10 @@ import MPCEthereumProvider
 
 
 extension MpcCoreKit : EvmSigner {
-    public func sign(message: Data) -> Data {
-        let data =  try? self.tssSign(message: message)
-        return data ?? Data([])
+    public func sign(message: Data) throws -> Data {
+        let data =  try self.tssSign(message: message)
+        return data
     }
-
 
     public var publicKey: Data {
         return self.getTssPubKey().suffix(64)