remove single-use lifetimes

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/service/rooms/state_cache/mod.rs

@@ -262,7 +262,7 @@ impl Service {
     }
 
     #[tracing::instrument(skip(self))]
-    pub fn server_in_room<'a>(&'a self, server: &ServerName, room_id: &RoomId) -> Result<bool> {
+    pub fn server_in_room(&self, server: &ServerName, room_id: &RoomId) -> Result<bool> {
         self.db.server_in_room(server, room_id)
     }