1. Run 4-card test only when single and 2-card test passed
2. rename file to make it more clear
3. remove useless pd workflow, it has been managed by nightly test
already.
- vLLM version: v0.11.2
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.2
Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>