[smg][ci] Migrate Response API e2e tests to shared infrastructure (#16680)

Co-authored-by: Chang Su <chang.s.su@oracle.com>
Co-authored-by: key4ng <rukeyang@gmail.com>

sgl-model-gateway/e2e_test/fixtures/hooks.py

@@ -377,6 +377,11 @@ def pytest_configure(config: pytest.Config) -> None:
         "markers",
         "thread_unsafe: mark test as incompatible with parallel thread execution",
     )
+    config.addinivalue_line(
+        "markers",
+        "storage(backend): mark test to use a specific history storage backend "
+        "(memory, oracle). Default is memory.",
+    )
 
 
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