skip L1 deactivation change utxos

mapper/pchain/tx_parser.go

@@ -765,7 +765,10 @@ func (t *TxParser) isMultisig(utxoid avax.UTXOID) (bool, error) {
 	utxoMap := dependencyTx.GetUtxos()
 	utxo, ok := utxoMap[utxoid]
 	if !ok {
-		return false, errFailedToCheckMultisig
+		// Consider the UTXO as multisig if it is not found in the dependency tx.
+		// Possible for dependency txs like [DisableL1ValidatorTx] or [SetL1ValidatorWeightTx].
+		// These unfound UTXOs are generated by the network but are not included in the tx bytes.
+		return true, nil
 	}
 
 	addressable, ok := utxo.Out.(avax.Addressable)