Let lighteval support sglang (#552)
You can use sglang in lighteval tasks
`lighteval sglang \
"pretrained=HuggingFaceH4/zephyr-7b-beta,dtype=float16" \
"helm|bigbench:bbq_lite_json:age_disambig|0|0"`
---------
Co-authored-by: Chayenne <zhaochenyang@ucla.edu>
Co-authored-by: qiujiang chen <qiujiang@lmsys.us-northcentral1-a.compute.internal>
