Add a couple extra Sync bounds

Not necessary right now, but required for axum 0.8.

src/api/ruma_wrapper/axum.rs

@@ -402,6 +402,7 @@ async fn ar_from_request_inner(
 impl<T, S> FromRequest<S> for Ar<T>
 where
     T: IncomingRequest,
+    S: Sync,
 {
     type Rejection = Error;
 

src/cli/serve.rs

@@ -209,13 +209,14 @@ struct ServerSpawner<'cfg, M> {
 
 impl<'cfg, M> ServerSpawner<'cfg, M>
 where
-    M: Layer<Route> + Clone + Send + 'static,
+    M: Layer<Route> + Clone + Send + Sync + 'static,
     M::Service: Service<
             axum::extract::Request,
             Response = axum::response::Response,
             Error = Infallible,
         > + Clone
         + Send
+        + Sync
         + 'static,
     <M::Service as Service<axum::extract::Request>>::Future: Send + 'static,
 {
@@ -936,7 +937,7 @@ macro_rules! impl_ruma_handler {
         where
             Req: IncomingRequest + Send + 'static,
             Resp: IntoResponse,
-            F: FnOnce($($ty,)* Ar<Req>) -> Fut + Clone + Send + 'static,
+            F: FnOnce($($ty,)* Ar<Req>) -> Fut + Clone + Send + Sync + 'static,
             Fut: Future<Output = Result<Resp, E>>
                 + Send,
             E: IntoResponse,