Make version mismatch warning informative and actionable

The old warning told users to downgrade, which is unhelpful when they
upgraded intentionally. The new message states both versions, notes that
there may be minor differences in defaults or behavior, and tells the
user to re-save the object to remove the warning.

Closes #4495

Author: h-mayorquin

src/spikeinterface/core/base.py

@@ -1151,7 +1151,8 @@ def _load_extractor_from_dict(dic) -> "BaseExtractor":
     if is_old_version:
         warnings.warn(
             f"This object was saved with {module_name}=={saved_version} and you are running {module_name}=={current_version}. "
-            f"To update the saved version, re-save the object with `save()` or `save_to_folder()`/`save_to_zarr()`."
+            f"This may lead to differences in default parameters or minor changes in behavior. "
+            f"To remove this warning, re-save the object with `save()` or `save_to_folder()`/`save_to_zarr()`."
         )
 
         if hasattr(extractor_class, "_handle_backward_compatibility"):