Move type Migrations to Config (#14309)

* move migrate sequence to config

* remove commented out code

* Update frame/contracts/src/lib.rs

Co-authored-by: PG Herveou <pgherveou@gmail.com>

* remove Migrations generic

* make runtime use noop migrations

* restrict is_upgrade_supported

* undo is_upgrade_supported change

* Update bin/node/runtime/src/lib.rs

Co-authored-by: PG Herveou <pgherveou@gmail.com>

* add rust doc example for `Migrations`

* feature gate NoopMigration

* fix example code

* improve example

---------

Co-authored-by: PG Herveou <pgherveou@gmail.com>

substrate/frame/contracts/src/tests.rs

@@ -28,8 +28,8 @@ use crate::{
 	wasm::{Determinism, PrefabWasmModule, ReturnCode as RuntimeReturnCode},
 	weights::WeightInfo,
 	BalanceOf, Code, CodeStorage, CollectEvents, Config, ContractInfo, ContractInfoOf, DebugInfo,
-	DefaultAddressGenerator, DeletionQueueCounter, Error, MigrationInProgress, Origin, Pallet,
-	Schedule,
+	DefaultAddressGenerator, DeletionQueueCounter, Error, MigrationInProgress, NoopMigration,
+	Origin, Pallet, Schedule,
 };
 use assert_matches::assert_matches;
 use codec::Encode;
@@ -428,6 +428,7 @@ impl Config for Test {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = UnstableInterface;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 
 pub const ALICE: AccountId32 = AccountId32::new([1u8; 32]);