feat(sdk): SlidingSyncList::handle_response must be pub(self).

This method must be only visible to the current module, not from the
upper/super module.

Note: `pub(self)` is equivalent to no `pub` at all.

crates/matrix-sdk/src/sliding_sync/list/mod.rs

@@ -313,7 +313,7 @@ impl SlidingSyncList {
     }
 
     #[instrument(skip(self, ops), fields(name = self.name, ops_count = ops.len()))]
-    pub(super) fn handle_response(
+    fn handle_response(
         &self,
         maximum_number_of_rooms: u32,
         ops: &Vec<v4::SyncOp>,