message: chore: immutably borrows from `tx_pool`
diff: @@ -394,7 +394,7 @@ impl<CS: ChainStore> ChainState<CS> {
  &self,
  tx: &'a Transaction,
  ) -> Result<ResolvedTransaction<'a>, UnresolvableError> {
  - let tx_pool = self.tx_pool.borrow_mut();
  + let tx_pool = self.tx_pool.borrow();
  let proposed_provider = OverlayCellProvider::new(&tx_pool.proposed, self);
  let gap_and_proposed_provider = OverlayCellProvider::new(&tx_pool.gap, &proposed_provider);
  let pending_and_proposed_provider =
  