enable unused_async lint

This also caused a "new" `unnecessary_wraps` lint to fire too, so that
got fixed too.

Cargo.toml

@@ -90,6 +90,7 @@ unneeded_field_pattern = "warn"
 unnested_or_patterns = "warn"
 unreadable_literal = "warn"
 unseparated_literal_suffix = "warn"
+unused_async = "warn"
 verbose_file_reads = "warn"
 wildcard_dependencies = "warn"
 

src/api/client_server/membership.rs

@@ -599,12 +599,12 @@ async fn join_room_by_id_helper(
                 .collect::<Vec<_>>()
             {
                 if user.server_name() == services().globals.server_name()
-                    && services()
+                    && services().rooms.state_accessor.user_can_invite(
-                        .rooms
+                        room_id,
-                        .state_accessor
+                        &user,
-                        .user_can_invite(room_id, &user, sender_user, &state_lock)
+                        sender_user,
-                        .await
+                        &state_lock,
-                        .unwrap_or(false)
+                    )
                 {
                     auth_user = Some(user);
                     break;

src/service/rooms/state_accessor.rs

@@ -310,13 +310,13 @@ impl Service {
             })
     }
 
-    pub(crate) async fn user_can_invite(
+    pub(crate) fn user_can_invite(
         &self,
         room_id: &RoomId,
         sender: &UserId,
         target_user: &UserId,
         state_lock: &MutexGuard<'_, ()>,
-    ) -> Result<bool> {
+    ) -> bool {
         let content = to_raw_value(&RoomMemberEventContent::new(MembershipState::Invite))
             .expect("Event content always serializes");
 
@@ -328,11 +328,11 @@ impl Service {
             redacts: None,
         };
 
-        Ok(services()
+        services()
             .rooms
             .timeline
             .create_hash_and_sign_event(new_event, sender, room_id, state_lock)
-            .is_ok())
+            .is_ok()
     }
 
     pub(crate) fn get_member(