Fix Python 3.10 compatibility by adding future annotations imports

Co-authored-by: bruAristimunha <[email protected]>

Author: Copilot

eegdash/features/extractors.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from abc import ABC, abstractmethod
 from collections.abc import Callable
 from functools import partial

eegdash/features/inspect.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import inspect
 from collections.abc import Callable
 

eegdash/features/serialization.py

@@ -6,6 +6,8 @@
 
 """
 
+from __future__ import annotations
+
 from pathlib import Path
 
 import pandas as pd