Soft deprecate GenesisConfig (#14210)

* soft deprecate genesisconfig

* temporarily add a deprecation attr

* update tests

* update mocks

* update genesis config

* update genesis config

* update genesis config

* update genesis config

* remove deprecation warning

* update deprecation comment

---------

Co-authored-by: parity-processbot <>

substrate/bin/utils/chain-spec-builder/src/main.rs

@@ -100,7 +100,7 @@ fn genesis_constructor(
 	nominator_accounts: &[AccountId],
 	endowed_accounts: &[AccountId],
 	sudo_account: &AccountId,
-) -> chain_spec::GenesisConfig {
+) -> chain_spec::RuntimeGenesisConfig {
 	let authorities = authority_seeds
 		.iter()
 		.map(AsRef::as_ref)