Add Migrations to contracts config (#2701)

* add Migrations to contracts config

* update lockfile for {"substrate", "polkadot"}

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Co-authored-by: parity-processbot <>

cumulus/parachains/runtimes/contracts/contracts-rococo/src/contracts.rs

@@ -48,4 +48,5 @@ impl Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<true>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+	type Migrations = ();
 }