Fix import Vec in admin-utils benchmarking

Author: ales-otf

pallets/admin-utils/src/benchmarking.rs

@@ -1,7 +1,9 @@
 //! Benchmarking setup
 #![cfg(feature = "runtime-benchmarks")]
 #![allow(clippy::arithmetic_side_effects)]
-use super::*;
+
+extern crate alloc;
+use alloc::vec::Vec;
 
 #[allow(unused)]
 use crate::Pallet as AdminUtils;
@@ -10,6 +12,8 @@ use frame_benchmarking::v2::*;
 use frame_support::BoundedVec;
 use frame_system::RawOrigin;
 
+use super::*;
+
 #[benchmarks]
 mod benchmarks {
     use super::*;