Fix _get_data and _set_data types

Author: basnijholt

adaptive/learner/average_learner1D.py

@@ -577,10 +577,10 @@ def tell_many_at_point(self, x: Real, seed_y_mapping: dict[int, Real]) -> None:
                     self._update_interpolated_loss_in_interval(*interval)
                 self._oldscale = deepcopy(self._scale)
 
-    def _get_data(self) -> dict[Real, Real]:
+    def _get_data(self) -> dict[Real, dict[Int, Real]]:
         return self._data_samples
 
-    def _set_data(self, data: dict[Real, Real]) -> None:
+    def _set_data(self, data: dict[Real, dict[Int, Real]]) -> None:
         if data:
             for x, samples in data.items():
                 self.tell_many_at_point(x, samples)