Update Pallet placeholder struct as per FRAME v2 (#14348)

* Update Pallet placeholder struct as per FRAME v3

* ".git/.scripts/commands/fmt/fmt.sh"

* Update lib.rs

Removed the unused import

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Co-authored-by: command-bot <>

substrate/test-utils/runtime/src/substrate_test_pallet.rs

@@ -45,7 +45,7 @@ pub mod pallet {
 
 	#[pallet::pallet]
 	#[pallet::without_storage_info]
-	pub struct Pallet<T>(PhantomData<T>);
+	pub struct Pallet<T>(_);
 
 	#[pallet::config]
 	pub trait Config: frame_system::Config {}