This proposal aims to reimburse 50 pool members that didn't receive various amounts of pool rewards due to [this bug](https://github.com/paritytech/polkadot-sdk/pull/3110), which was fixed in the latest runtime upgrade. 

In short, when a pool enters the destroying phase anyone can permissionlessly unbond the pool members. When that happens any pending rewards are claimed. This bug caused the rewards to be sent to the caller of the `unbond` extrinsic, instead of the actual pool member.

We ran [this Python script](https://gist.github.com/michalisFr/a59d9da2b346a581aa8dedc171393534) to find the affected accounts and the rewards they didn't receive (credit to Kian who wrote it). The results can be found [here](https://drive.google.com/file/d/1gH6N-5YSz9Ip6UYv5MDc47_ePKpC2GbU/view?usp=sharing). I'd appreciate any cross checks to make sure the batch call has been built correctly and the proper amounts will be sent to the correct recipients.

To be clear, this is a double spend. These rewards have already been claimed by the pool owners who called the `unbond` extrinsics. But given that the amount is small, and trying to contact all these pool owners to return the misappropriated rewards would be troublesome to say the least, we believe this proposal is the most straightforward way to make these pool members whole and we'd appreciate it if the community approved it.

- **Problem Statement:** Reimbursement for 50 pool members who did not receive rewards due to a bug in the Polkadot system.
- **Significance:** Bug caused rewards to be sent to the wrong recipients, impacting pool members' earnings.
- **Proposed Solution:** Reimburse affected pool members for the missed rewards.
- **Expected Outcomes:** Restoring fairness by rectifying the missed rewards for the impacted pool members.

Requested: 0.21 undefined

#663 Reimbursement for lost pool rewards