GitLab

* purge HF_HUB_ENABLE_HF_TRANSFER; promote Xet

* purge HF_HUB_ENABLE_HF_TRANSFER; promote Xet x2

* restrict docker build test to the ones we actually use in CI.

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Co-authored-by: YiYi Xu <yixu310@gmail.com>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>