Explicit reexport of types (#2866) (#2913)

Explicitly reexport types to make strict mypy setups happy. This backports #2866 to 1.x.

Fixes GH-2910

Co-authored-by: Anton Pirker <anton.pirker@sentry.io>

Author: szokeasaurusrex

sentry_sdk/types.py

@@ -12,3 +12,5 @@
 
 if TYPE_CHECKING:
     from sentry_sdk._types import Event, Hint  # noqa: F401
+
+    __all__ = ["Event", "Hint"]