Motion 13 is submitted: Polkadot runtime update to v23

Upgrade priority: MEDIUM

Specs of the runtime can be found [here](https://github.com/paritytech/polkadot/releases/tag/v0.8.23).

All Councillors please vote at your convenience. The preimage can be verified in the release notes.

 Schedule a majority-carries referendum to be tabled next once it is legal to schedule
 an external referendum.

 The dispatch of this call must be `ExternalMajorityOrigin`.

 - `proposal_hash`: The preimage hash of the proposal.

 Unlike `external_propose`, blacklisting has no effect on this and it may replace a
 pre-scheduled `external_propose` call.

 # <weight>
 - Complexity: `O(1)`
 - Db write: `NextExternal`
 - Base Weight: 3.065 µs
 # </weight>

- There is a motion to update Polkadot runtime to version 23.
- The upgrade priority is medium.
- The specifications of the runtime can be found at a specific website.
- All council members are asked to vote on this motion.
- There is a shorter summary at the end called "Tl;dr".

#13 SetCode: Polkadot runtime v23