bump gnark version to 0.12

Author: Mechanix97

go.mod

@@ -13,7 +13,7 @@ require (
 require (
 	github.com/AdaLogics/go-fuzz-headers v0.0.0-20240806141605-e8a1dd7889d6
 	github.com/cenkalti/backoff/v4 v4.3.0
-	github.com/consensys/gnark v0.10.0
+	github.com/consensys/gnark v0.12.0
 	github.com/consensys/gnark-crypto v0.12.2-0.20240215234832-d72fcb379d3e
 	github.com/fxamacker/cbor/v2 v2.7.0
 	github.com/ugorji/go/codec v1.2.12