Remove mention of LoadedDL handle in README.md (it was an oversight that this wasn't removed before).

Author: rwgk

cuda_pathfinder/cuda/pathfinder/README.md

@@ -7,7 +7,6 @@
 * `cuda.pathfinder.load_nvidia_dynamic_lib(libname: str) -> LoadedDL`
 
 * `cuda.pathfinder.LoadedDL`:
-    * `handle` (platform-specific type)
     * `abs_path` (`str`)
     * `was_already_loaded_from_elsewhere` (`bool`)