test: update tests accordingly

tests/fetchers/async/test_dynamic_session.py

@@ -43,7 +43,7 @@ class TestAsyncDynamicSession:
             assert stats["total_pages"] <= 3
 
         # After exit, should be closed
-        assert session._closed is True
+        assert session._is_alive is False
 
         # Should raise RuntimeError when used after closing
         with pytest.raises(RuntimeError):

tests/fetchers/async/test_stealth_session.py

@@ -44,7 +44,7 @@ class TestAsyncStealthySession:
             assert stats["total_pages"] <= 3
 
         # After exit, should be closed
-        assert session._closed is True
+        assert session._is_alive is False
 
         # Should raise RuntimeError when used after closing
         with pytest.raises(RuntimeError):