Remove staking v12 migration

substrate/bin/node/runtime/src/lib.rs

@@ -1856,67 +1856,6 @@ pub type Executive = frame_executive::Executive<
 >;
 
 
-// staking is only expected to be used by polkadot/kusama/et al., so they didn't
-// bother to bump the default storage version. as such, we have V7_0_0 version
-// set, but it's actually the layout of V12. Fix it before running V13 migration.
-mod staking_v12 {
-	use super::*;
-	use frame_support::{storage_alias, traits::OnRuntimeUpgrade, pallet_prelude::*};
-
-	#[derive(Encode, Decode, Clone, Copy, PartialEq, Eq, RuntimeDebug, TypeInfo, MaxEncodedLen)]
-	enum ObsoleteReleases {
-		V1_0_0Ancient,
-		V2_0_0,
-		V3_0_0,
-		V4_0_0,
-		V5_0_0,
-		V6_0_0,
-		V7_0_0,
-		V8_0_0,
-		V9_0_0,
-		V10_0_0,
-		V11_0_0,
-		V12_0_0,
-	}
-
-	impl Default for ObsoleteReleases {
-		fn default() -> Self {
-			Self::V12_0_0
-		}
-	}
-
-	#[storage_alias]
-	type StorageVersion<T: pallet_staking::Config> = StorageValue<pallet_staking::Pallet<T>, ObsoleteReleases, ValueQuery>;
-
-	pub struct Migration<T>(sp_std::marker::PhantomData<T>);
-	impl<T: pallet_staking::Config> OnRuntimeUpgrade for Migration<T> {
-		#[cfg(feature = "try-runtime")]
-		fn pre_upgrade() -> Result<Vec<u8>, sp_runtime::TryRuntimeError> {
-			frame_support::ensure!(
-                StorageVersion::<T>::get() == ObsoleteReleases::V7_0_0,
-                "Expected v7 before upgrading to v12"
-            );
-
-            Ok(Default::default())
-		}
-
-		fn on_runtime_upgrade() -> Weight {
-			StorageVersion::<T>::put(ObsoleteReleases::V12_0_0);
-			log::info!("Migrated pallet-staking StorageVersion to V12");
-			T::DbWeight::get().reads_writes(1, 1)
-		}
-
-		#[cfg(feature = "try-runtime")]
-		fn post_upgrade(_: Vec<u8>) -> Result<(), sp_runtime::TryRuntimeError> {
-			frame_support::ensure!(
-                StorageVersion::<T>::get() == ObsoleteReleases::V12_0_0,
-                "Failed to upgrade to v12"
-            );
-			Ok(())
-		}
-	}
-}
-
 // All migrations executed on runtime upgrade as a nested tuple of types implementing
 // `OnRuntimeUpgrade`.
 type Migrations = (