Hacky way to get Python3.8 compatability

modal/_container_entrypoint.py

@@ -59,7 +59,13 @@
 from .partial_function import _find_callables_for_obj, _PartialFunctionFlags
 
 if TYPE_CHECKING:
-    from types import ModuleType, TracebackType
+    from types import ModuleType
+
+    try:
+        from types import TracebackType
+    except ImportError:
+        # Python 3.8
+        TracebackType = Any
 
 ExceptionInfo = Tuple[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]]