This is a referendum to upgrade Polkadot to the Fellowship's [v.1.20 release](https://github.com/polkadot-fellows/runtimes/releases/tag/v1.2.0).

See [`Pallet::dispatch_whitelisted_call_with_preimage`].

- **Problem Statement:** Upgrading Polkadot to the Fellowship's v1.20 release.
- **Significance:** Enhancing Polkadot's functionality and security.
- **Proposed Solution:** Approve the upgrade to the v1.20 release.
- **Expected Outcomes:** Improved performance and security for Polkadot users.

#648 Upgrade Polkadot to Release v1.2.0