This Referendum registers the People Chain and gives it a core straight away.

To avoid having to wait for two sale boundaries for the People Chain to be given a core, the Coretime Chain is also upgraded to the [Fellowship v1.2.3 release](https://github.com/polkadot-fellows/runtimes/releases/tag/v1.2.3).

This upgrade to the Coretime Chain includes a migration to reserve a core for the people chain without delay. It also cleans up some entries in storage from the old sale.

See [`Pallet::dispatch_whitelisted_call_with_preimage`].

- Problem Statement: Registering the People Chain and providing it with a core immediately.
- Significance: Avoiding delays in assigning a core to the People Chain and upgrading the Coretime Chain to Fellowship v1.2.3 release.
- Proposed Solution: Upgrading the Coretime Chain to allocate a core for the People Chain promptly and cleaning up old storage entries.
- Expected Outcomes: Efficient allocation of cores for the People Chain and improved functionality in the Coretime Chain.

#384 Register People Chain and upgrade Coretime Chain to v1.2.3