Refresh the progress bars on exit

Because we don't update the progress bars on every iteration, it is
possible that we finish without the bars reaching 100%, specially in
very small files. The progress bars normally dissapear so this is not
much of a problem, but in Jypiter notebooks the output may linger,
making it a bit confusing.

To avoid this problem, emit a last refresh on exit that updates the
status of the progress bars to 100%.

Signed-off-by: Pablo Galindo <[email protected]>

src/memray/_memray.pyx

@@ -808,6 +808,7 @@ cdef class ProgressIndicator:
     def __exit__(self, type, value, traceback):
         if not self._report_progress:
             return
+        self._context_manager.update(self._task, completed=self._cumulative_num_processed)
         return self._context_manager.__exit__(type, value, traceback)
 
     cdef bool _time_for_refresh(self):