fix: add type hint to __lazy_modules__

Author: hebaalazzeh

packages/google-auth/google/auth/transport/__init__.py

@@ -30,7 +30,9 @@
 # For more information, see:
 # https://docs.python.org/3.15/library/sys.html#sys.set_lazy_imports_filter
 # Older Python versions safely ignore this variable.
-__lazy_modules__ = {
+from typing import Set
+
+__lazy_modules__: Set[str] = {
     "_aiohttp_requests",
     "_custom_tls_signer",
     "_http_client",