[CI] Automatic Shinjuku Upgrade During Release

[Dinonard]

Description

Shinjuku is a low-value test parachain on internal Astar test network.

What we'd like to do is to automatically upgrade it with Shibuya wasm binary each time a new release is made.
Prior to the actual upgrade, some sanity checks (e.g. chopsticks upgrade procedure) should be done.

Sudo key should be made into multisig with threshold set to 1, and private key of the Github runner account should be stored as a secret. This key, even though has sudo rights, will be relatively low value since it refers to low value testnetwork.

This should be done during the release procedure.