Remove deprecated Extension import alias

RELEASE.md

@@ -0,0 +1,21 @@
+Release type: minor
+
+Remove deprecated `Extension` import alias from `strawberry.extensions`, deprecated since [0.160.0](https://github.com/strawberry-graphql/strawberry/releases/tag/0.160.0).
+
+### Migration guide
+
+**Before (deprecated):**
+```python
+from strawberry.extensions import Extension
+
+
+class MyExtension(Extension): ...
+```
+
+**After:**
+```python
+from strawberry.extensions import SchemaExtension
+
+
+class MyExtension(SchemaExtension): ...
+```

strawberry/extensions/__init__.py

@@ -1,5 +1,3 @@
-import warnings
-
 from .add_validation_rules import AddValidationRules
 from .base_extension import LifecycleStep, SchemaExtension
 from .disable_introspection import DisableIntrospection
@@ -12,22 +10,6 @@
 from .query_depth_limiter import IgnoreContext, QueryDepthLimiter
 from .validation_cache import ValidationCache
 
-
-def __getattr__(name: str) -> type[SchemaExtension]:
-    if name == "Extension":
-        warnings.warn(
-            (
-                "importing `Extension` from `strawberry.extensions` "
-                "is deprecated, import `SchemaExtension` instead."
-            ),
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return SchemaExtension
-
-    raise AttributeError(f"module {__name__} has no attribute {name}")
-
-
 __all__ = [
     "AddValidationRules",
     "DisableIntrospection",