Disable old redeemer deserialization

Author: Soupstraw

eras/alonzo/impl/src/Cardano/Ledger/Alonzo/TxWits.hs

@@ -578,7 +578,11 @@ instance AlonzoEraScript era => DecCBOR (Annotator (RedeemersRaw era)) where
       ( peekTokenType >>= \case
           TypeMapLenIndef -> decodeMapRedeemers
           TypeMapLen -> decodeMapRedeemers
-          _ -> decodeListRedeemers
+          _ ->
+            ifDecoderVersionAtLeast
+              (natVersion @12)
+              (fail "List encoding of redeemers not supported starting with PV 12")
+              decodeListRedeemers
       )
       ( mapTraverseableDecoderA
           (decodeList decodeAnnElement)

eras/alonzo/impl/testlib/Test/Cardano/Ledger/Alonzo/Binary/Annotator.hs

@@ -209,7 +209,11 @@ instance AlonzoEraScript era => DecCBOR (RedeemersRaw era) where
       ( peekTokenType >>= \case
           TypeMapLenIndef -> decodeMapRedeemers
           TypeMapLen -> decodeMapRedeemers
-          _ -> decodeListRedeemers
+          _ ->
+            ifDecoderVersionAtLeast
+              (natVersion @12)
+              (fail "List encoding of redeemers not supported starting with PV 12")
+              decodeListRedeemers
       )
       (RedeemersRaw . Map.fromList <$> decodeList decodeElement)
     where