Fix typing.Self not being available on Python 3.10

Summary: The pyrefly tests are failing as a result of this import.

Reviewed By: martindemello

Differential Revision: D96511508

fbshipit-source-id: 40918d30c16c4801081c050a84f9221a7ef4d590

Author: alexmalyshev

cinderx/PythonLib/cinderx/compiler/static/pyrefly_info.py

@@ -8,7 +8,7 @@
 import os
 from ast import AST, Attribute
 from dataclasses import dataclass
-from typing import Self, TypedDict
+from typing import TypedDict
 
 from cinderx.compiler.static.module_table import ModuleTable
 from cinderx.compiler.static.types import (
@@ -19,6 +19,14 @@
     Value,
 )
 
+# Remove this once we drop the Python 3.10 tests.
+try:
+    from typing import Self
+except ImportError:
+    from typing import TypeVar
+
+    Self = TypeVar("T", bound="Self")
+
 
 class Location(TypedDict):
     start_line: int