Disabled validators runtime API (#1257)

Exposes disabled validators list via a runtime API.

---------

Co-authored-by: ordian <noreply@reusable.software>
Co-authored-by: ordian <write@reusable.software>

cumulus/parachains/integration-tests/emulated/common/src/lib.rs

@@ -33,7 +33,7 @@ use xcm_emulator::{
 };
 
 decl_test_relay_chains! {
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Westend {
 		genesis = westend::genesis(),
 		on_init = (),
@@ -50,7 +50,7 @@ decl_test_relay_chains! {
 			AssetRate: westend_runtime::AssetRate,
 		}
 	},
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Rococo {
 		genesis = rococo::genesis(),
 		on_init = (),
@@ -65,7 +65,7 @@ decl_test_relay_chains! {
 			Balances: rococo_runtime::Balances,
 		}
 	},
-	#[api_version(7)]
+	#[api_version(8)]
 	pub struct Wococo {
 		genesis = rococo::genesis(),
 		on_init = (),