Use typing_extensions.Self as fallback (fixes #902)

src/dependency_injector/containers.pyi

@@ -17,6 +17,9 @@ from typing import (
     overload,
 )
 
+try:
+    from typing import Self as _Self
+except ImportError:
     from typing_extensions import Self as _Self
 
 from .providers import Provider, ProviderParent, Self

src/dependency_injector/wiring.py

@@ -25,6 +25,9 @@ from typing import (
     cast,
 )
 
+try:
+    from typing import Self
+except ImportError:
     from typing_extensions import Self
 
 try: