CDDL: Make plutus_v2_script era generic

Author: aniketd

eras/babbage/impl/cddl/lib/Cardano/Ledger/Babbage/HuddleSpec.hs

@@ -9,6 +9,7 @@
 {-# LANGUAGE QuasiQuotes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE UndecidableInstances #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
 
 module Cardano.Ledger.Babbage.HuddleSpec (
@@ -451,7 +452,7 @@ instance HuddleGroup "script_invalid_before" BabbageEra where
 instance HuddleGroup "script_invalid_hereafter" BabbageEra where
   huddleGroup = scriptInvalidHereafterGroup @BabbageEra
 
-instance HuddleRule "plutus_v2_script" BabbageEra where
+instance (Era era, HuddleRule "distinct_bytes" era) => HuddleRule "plutus_v2_script" era where
   huddleRule p =
     comment
       [str|Babbage introduces Plutus V2 with improved cost model

eras/conway/impl/cddl/lib/Cardano/Ledger/Conway/HuddleSpec.hs

@@ -636,14 +636,6 @@ instance HuddleRule "operational_cert" ConwayEra where
 instance HuddleRule "protocol_version" ConwayEra where
   huddleRule = babbageProtocolVersionRule @ConwayEra
 
-instance HuddleRule "plutus_v2_script" ConwayEra where
-  huddleRule p =
-    comment
-      [str|Babbage introduces Plutus V2 with improved cost model
-          |and additional builtins.
-          |]
-      $ "plutus_v2_script" =:= huddleRule @"distinct_bytes" p
-
 instance HuddleRule "plutus_v3_script" ConwayEra where
   huddleRule p =
     comment