Remove assert from tracking provider

This assert would be triggered every time a memory
is leaked by the application. Currently this happens in
certain SYCL tests.

Author: igchor

src/provider/provider_tracking.c

@@ -405,7 +405,6 @@ static void check_if_tracker_is_empty(umf_memory_tracker_handle_t hTracker,
                         "left)",
                         n_items);
             }
-            assert(n_items == 0);
         }
     }
 }