chore: remove default upgrade height v2 from this backport

cmd/celestia-appd/cmd/start.go

@@ -118,20 +118,6 @@ is performed. Note, when enabled, gRPC will also be automatically enabled.
 				return err
 			}
 
-			switch clientCtx.ChainID {
-			case appconsts.ArabicaChainID:
-				serverCtx.Logger.Info(fmt.Sprintf("Since the chainID is %v, configuring the default v2 upgrade height to %v", appconsts.ArabicaChainID, appconsts.ArabicaUpgradeHeightV2))
-				serverCtx.Viper.SetDefault(UpgradeHeightFlag, appconsts.ArabicaUpgradeHeightV2)
-			case appconsts.MochaChainID:
-				serverCtx.Logger.Info(fmt.Sprintf("Since the chainID is %v, configuring the default v2 upgrade height to %v", appconsts.MochaChainID, appconsts.MochaUpgradeHeightV2))
-				serverCtx.Viper.SetDefault(UpgradeHeightFlag, appconsts.MochaUpgradeHeightV2)
-			case appconsts.MainnetChainID:
-				serverCtx.Logger.Info(fmt.Sprintf("Since the chainID is %v, configuring the default v2 upgrade height to %v", appconsts.MainnetChainID, appconsts.MainnetUpgradeHeightV2))
-				serverCtx.Viper.SetDefault(UpgradeHeightFlag, appconsts.MainnetUpgradeHeightV2)
-			default:
-				serverCtx.Logger.Info(fmt.Sprintf("No default value exists for the v2 upgrade height when the chainID is %v", clientCtx.ChainID))
-			}
-
 			if contains(appconsts.PublicNetworks, clientCtx.ChainID) && serverCtx.Viper.GetDuration(TimeoutCommitFlag) != 0 {
 				return fmt.Errorf("the --timeout-commit flag was used on %v but it is unsupported on public networks: %v. The --timeout-commit flag should only be used on private testnets", clientCtx.ChainID, strings.Join(appconsts.PublicNetworks, ", "))
 			}