[serve] [CI] change serve:test_runtime_env from medium to large (#22474)
[serve] [CI] change serve:test_runtime_env from medium to large (#22474)

This test was timing out occasionally.
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray