Use metadata to detect version of package

[kebe7jun]

Fix #4781

[junliu-mde]

Thanks for working on that. I wonder whether it's convenient if simply using the hash string, because it's not easy to figure out what the release version that hash string is corresponding to.

[kebe7jun]

The output is in semver format, not a hash.

[kebe7jun]

In [3]: get_package_versions(PACKAGE_LIST)
Out[3]: 
{'sglang': '0.4.3.post4',
 'sgl_kernel': '0.0.3.post6',
 'flashinfer': 'Module Not Found',
 'triton': '3.1.0',
 'transformers': '4.48.3',
 'torchao': '0.9.0',
 'numpy': '1.26.4',
 'aiohttp': '3.11.13',
 'fastapi': '0.115.11',
 'hf_transfer': '0.1.9',