Update develop to patch-polkadot-sdk

Allows us to finally remove the old `serai-dex/substrate` repository _and_
should have CI pass without issue on `develop` again.

The changes made here should be trivial and maintain all prior
behavior/functionality. The most notable are to `chain_spec.rs`, in order to
still use a SCALE-encoded `GenesisConfig` (avoiding `serde_json`).

substrate/genesis-liquidity/pallet/src/lib.rs

@@ -40,7 +40,6 @@ pub mod pallet {
     + CoinsConfig
     + coins_pallet::Config<coins_pallet::Instance1>
   {
-    type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
   }
 
   #[pallet::error]