Due to a [bug](https://github.com/paritytech/substrate/issues/13534) in Substrate version 0.9.40, preimages of proposals cannot simply be removed after the proposal was successful as they are still considered to be "Requested", although they should actually go back to the status "Unrequested".

With this referendum, we want to manually un-request the stale preimages so that they can later be unnoted as they should. 

Send a batch of dispatch calls and atomically execute them.
The whole transaction will rollback and fail if any of the calls failed.

May be called from any origin except `None`.

- `calls`: The calls to be dispatched from the same origin. The number of call must not
  exceed the constant: `batched_calls_limit` (available in constant metadata).

If origin is root then the calls are dispatched without checking origin filter. (This
includes bypassing `frame_system::Config::BaseCallFilter`).

## Complexity
- O(C) where C is the number of calls to be batched.

- Problem Statement: Difficulty in removing preimages of successful proposals in Substrate version 0.9.40, affecting the council's ability to manage proposal statuses.
- Significance: Ensuring accurate status updates for preimages is crucial for maintaining proposal integrity and transparency.
- Proposed Solution: Manually un-request stale preimages to correct their status from "Requested" to "Unrequested."
- Expected Outcomes: Improved proposal management efficiency and accuracy in Substrate version 0.9.40.

#44 Remove old preimages for referenda