Update IntermediateStateRoot after substrate upgrade

[boundless-forest]

Relate Prs:

1. Substrate side: Inner hashing of value in state trie (runtime versioning). paritytech/substrate#9732
2. Frontier side: https://github.com/paritytech/frontier/pull/583/files#diff-4a4404da981c8fc7fd4a5f9245136407d480ae2568de69e207c12066cb9473f5

pub struct IntermediateStateRoot<T>(PhantomData<T>);
impl<T: Config> Get<H256> for IntermediateStateRoot<T> {
	fn get() -> H256 {
		let version = T::Version::get().state_version();  // this line
		H256::decode(&mut &sp_io::storage::root(version)[..])
			.expect("Node is configured to use the same hash; qed")
	}
}

[boundless-forest]

Related commit: darwinia-network/substrate@6ee7b44