Rococo AH: cleanup storage (#4444)

Follow up on #4414 to clean up the old storage.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs

@@ -992,10 +992,15 @@ pub type Migrations = (
 	cumulus_pallet_xcmp_queue::migration::v4::MigrationToV4<Runtime>,
 	cumulus_pallet_xcmp_queue::migration::v5::MigrateV4ToV5<Runtime>,
 	pallet_collator_selection::migration::v2::MigrationToV2<Runtime>,
+	frame_support::migrations::RemovePallet<StateTrieMigrationName, RocksDbWeight>,
 	// permanent
 	pallet_xcm::migration::MigrateToLatestXcmVersion<Runtime>,
 );
 
+parameter_types! {
+	pub const StateTrieMigrationName: &'static str = "StateTrieMigration";
+}
+
 /// Migration to initialize storage versions for pallets added after genesis.
 ///
 /// This is now done automatically (see <https://github.com/paritytech/polkadot-sdk/pull/1297>),

prdoc/pr_4444.prdoc

+title: "Rococo AH: cleanup storage"
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Remove old storage that is left over in the Rococo AH storage.
+
+crates:
+  - name: asset-hub-rococo-runtime
+    bump: patch