Revert "[Runtime] Bound XCMP queue" (#3117)

Reverts paritytech/polkadot-sdk#2302. 🤦‍♂️ should have checked the
migration CI first.

We either need to reduce the `max_message_size` for the open HRMP
channels on the failing chains or increase the `PageSize` of the XCMP
queue.
Both would be fine on a test-net, but i assume this will also fail
before the next SP runtime upgrade so first need to think what best to
do.
AFAIK its not possible currently to change the `max_message_size` of an
open HRMP channel.

cumulus/pallets/parachain-system/src/lib.rs

@@ -30,7 +30,7 @@
 use codec::{Decode, Encode};
 use cumulus_primitives_core::{
 	relay_chain, AbridgedHostConfiguration, ChannelInfo, ChannelStatus, CollationInfo,
-	GetChannelInfo, InboundDownwardMessage, InboundHrmpMessage, ListChannelInfos, MessageSendError,
+	GetChannelInfo, InboundDownwardMessage, InboundHrmpMessage, MessageSendError,
 	OutboundHrmpMessage, ParaId, PersistedValidationData, UpwardMessage, UpwardMessageSender,
 	XcmpMessageHandler, XcmpMessageSource,
 };
@@ -1023,13 +1023,6 @@ impl<T: Config> FeeTracker for Pallet<T> {
 	}
 }
 
-impl<T: Config> ListChannelInfos for Pallet<T> {
-	fn outgoing_channels() -> Vec<ParaId> {
-		let Some(state) = Self::relevant_messaging_state() else { return Vec::new() };
-		state.egress_channels.into_iter().map(|(id, _)| id).collect()
-	}
-}
-
 impl<T: Config> GetChannelInfo for Pallet<T> {
 	fn get_channel_status(id: ParaId) -> ChannelStatus {
 		// Note, that we are using `relevant_messaging_state` which may be from the previous