Fix xcm-builder mock (#7652)

* Fix xcm-builder mock

(preparation for monorepo)

The CI fails here when the runtime-benchmarks feature is enabled in the workspace.

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

* Update xcm/xcm-builder/Cargo.toml

---------

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

polkadot/xcm/xcm-builder/Cargo.toml

@@ -42,6 +42,7 @@ runtime-benchmarks = [
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
 	"xcm-executor/runtime-benchmarks",
+	"pallet-assets/runtime-benchmarks",
 ]
 std = [
 	"log/std",

polkadot/xcm/xcm-builder/src/tests/pay/mock.rs

@@ -119,6 +119,8 @@ impl pallet_assets::Config for Test {
 	type RemoveItemsLimit = RemoveItemsLimit;
 	type AssetIdParameter = AssetIdForAssets;
 	type CallbackHandle = ();
+	#[cfg(feature = "runtime-benchmarks")]
+	type BenchmarkHelper = ();
 }
 
 parameter_types! {