Remove bounds from PrevalidateAttests struct definition (#2886)

Removing some bounds as it came up in
https://github.com/paritytech/polkadot-sdk/pull/2726 while still keeping
`Send + Sync` capabilities.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>

polkadot/runtime/common/src/claims.rs

@@ -591,11 +591,9 @@ impl<T: Config> Pallet<T> {
 /// otherwise free to place on chain.
 #[derive(Encode, Decode, Clone, Eq, PartialEq, TypeInfo)]
 #[scale_info(skip_type_params(T))]
-pub struct PrevalidateAttests<T: Config + Send + Sync>(sp_std::marker::PhantomData<T>)
-where
-	<T as frame_system::Config>::RuntimeCall: IsSubType<Call<T>>;
+pub struct PrevalidateAttests<T>(core::marker::PhantomData<fn(T)>);
 
-impl<T: Config + Send + Sync> Debug for PrevalidateAttests<T>
+impl<T: Config> Debug for PrevalidateAttests<T>
 where
 	<T as frame_system::Config>::RuntimeCall: IsSubType<Call<T>>,
 {
@@ -610,7 +608,7 @@ where
 	}
 }
 
-impl<T: Config + Send + Sync> PrevalidateAttests<T>
+impl<T: Config> PrevalidateAttests<T>
 where
 	<T as frame_system::Config>::RuntimeCall: IsSubType<Call<T>>,
 {
@@ -620,7 +618,7 @@ where
 	}
 }
 
-impl<T: Config + Send + Sync> SignedExtension for PrevalidateAttests<T>
+impl<T: Config> SignedExtension for PrevalidateAttests<T>
 where
 	<T as frame_system::Config>::RuntimeCall: IsSubType<Call<T>>,
 {

prdoc/pr_2886.prdoc

@@ -0,0 +1,13 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: Remove bounds from `PrevalidateAttests` struct definition
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Minimal change to `PrevalidateAssets` to remove some trait bounds on the struct itself while
+      keeping all its capabilities.
+
+crates:
+  - name: polkadot-runtime-common