### What problem does this PR solve?
MinerU supports VLM-Transfomers backend.
Set `MINERU_BACKEND="pipeline"` to choose the backend. (Options:
pipeline | vlm-transformers, default is pipeline)
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
Add MinerU parser. #3945, #8092.
Set `MINERU_EXECUTABLE` to the MinerU executable path, defaults to
`mineru`.
Set `MINERU_DELETE_OUTPUT=0` to preserve MinerU's output, default is 1,
which deletes temporary output.
Set `MINERU_OUTPUT_DIR` to choose the MinerU output directory (uses the
temporary directory if unset).
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
