polkadot-parachain: one chain-spec for all (#2457)
This PR removes some `ChainSpec` types which are not necessary (left-overs from #1256). Currently `ChainSpec` does not have to be generic over the specific `RuntimeGenesisConfig`, it is enough to use single type for all: https://github.com/paritytech/polkadot-sdk/blob/9f787018/cumulus/polkadot-parachain/src/chain_spec/mod.rs#L53-L54 related to: https://github.com/paritytech/polkadot-sdk/issues/25 --------- Co-authored-by: command-bot <>