[ci] Stop syncer staging tests (#26273)
[ci] Stop syncer staging tests (#26273)

The tests has been running for 1-2 months, and the overall observation is that it's not very useful to catch the actual regression. Basically, we didn't notice any regression. Stop this test for now to save some resources.


ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray