fix uv sync bug

[CzealChen]

warning:VIRTUAL_ENV=/root/nano-vllm/.venvdoes not match the project environment path.venvand will be ignored; use--activeto target the active environment instead Using CPython 3.11.13 Creating virtual environment at: .venv Resolved 47 packages in 5.30s × Failed to buildflash-attn==2.8.3├─▶ The build backend returned an error ╰─▶ Call tosetuptools.build_meta:legacy.build_wheel` failed (exit status: 1)

  [stderr]
  Traceback (most recent call last):
    File "<string>", line 14, in <module>
    File "/root/.cache/uv/builds-v0/.tmpdTSVzt/lib/python3.11/site-packages/setuptools/build_meta.py", line 331, in get_requires_for_build_wheel
      return self._get_build_requires(config_settings, requirements=[])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/root/.cache/uv/builds-v0/.tmpdTSVzt/lib/python3.11/site-packages/setuptools/build_meta.py", line 301, in _get_build_requires
      self.run_setup()
    File "/root/.cache/uv/builds-v0/.tmpdTSVzt/lib/python3.11/site-packages/setuptools/build_meta.py", line 512, in run_setup
      super().run_setup(setup_script=setup_script)
    File "/root/.cache/uv/builds-v0/.tmpdTSVzt/lib/python3.11/site-packages/setuptools/build_meta.py", line 317, in run_setup
      exec(code, locals())
    File "<string>", line 22, in <module>
  ModuleNotFoundError: No module named 'torch'

  hint: This error likely indicates that `[email protected]` depends on `torch`, but doesn't declare it as a build dependency. If `flash-attn` is a first-party package, consider
  adding `torch` to its `build-system.requires`. Otherwise, either add it to your `pyproject.toml` under:

  [tool.uv.extra-build-dependencies]
  flash-attn = ["torch"]

  or `uv pip install torch` into the environment and re-run with `--no-build-isolation`.

help: flash-attn (v2.8.3) was included because nano-vllm (v0.2.0) depends on `flash-attn``

fix this install bug .