Filter votes from disabled validators in BackedCandidates in process_inherent_data (#2889)

Backport of https://github.com/paritytech/polkadot-sdk/pull/1863 to
master

Extend candidate sanitation in paras_inherent by removing backing votes
from disabled validators. Check
https://github.com/paritytech/polkadot-sdk/issues/1592 for more details.

This change is related to the disabling strategy implementation
(https://github.com/paritytech/polkadot-sdk/pull/2226).

---------

Co-authored-by: ordian <noreply@reusable.software>
Co-authored-by: ordian <write@reusable.software>
Co-authored-by: Maciej <maciej.zyszkiewicz@parity.io>

polkadot/runtime/parachains/src/runtime_api_impl/vstaging.rs

@@ -21,29 +21,16 @@ use primitives::{
 	vstaging::{ApprovalVotingParams, NodeFeatures},
 	ValidatorIndex,
 };
-use sp_std::{collections::btree_map::BTreeMap, prelude::Vec};
+use sp_std::prelude::Vec;
 
 /// Implementation for `DisabledValidators`
 // CAVEAT: this should only be called on the node side
 // as it might produce incorrect results on session boundaries
 pub fn disabled_validators<T>() -> Vec<ValidatorIndex>
 where
-	T: pallet_session::Config + shared::Config,
+	T: shared::Config,
 {
-	let shuffled_indices = <shared::Pallet<T>>::active_validator_indices();
-	// mapping from raw validator index to `ValidatorIndex`
-	// this computation is the same within a session, but should be cheap
-	let reverse_index = shuffled_indices
-		.iter()
-		.enumerate()
-		.map(|(i, v)| (v.0, ValidatorIndex(i as u32)))
-		.collect::<BTreeMap<u32, ValidatorIndex>>();
-
-	// we might have disabled validators who are not parachain validators
-	<pallet_session::Pallet<T>>::disabled_validators()
-		.iter()
-		.filter_map(|v| reverse_index.get(v).cloned())
-		.collect()
+	<shared::Pallet<T>>::disabled_validators()
 }
 
 /// Returns the current state of the node features.