[Feat][CI] Enable LLMC integration test

[yiliu30]

• Add LLMC UT in auto-round test @yiliu30 Add LLMC integration test #1053
• Install the LLMC from a specific commit (we’ll switch to the release version later)
  Something we need to address:
  We have pinned the auto-round in LLMC. [AutoRound] Update autoround to the release version vllm-project/llm-compressor#2062
  How can we install AutoRound from the test branch? @XuehaoSun cc @chensuyue

cc @xin3he @thuang6 @wenhuach21