Add lower bounds for fsspec and networkx dependencies (#158565)

Fixes #156587

This sets lower bounds for fsspec and networkx in both setup.py and requirements,txt.

- fsspec>= 0.8.5 (released December 15, 2020)
- netowrkx>= 2.5.1 (released April 3, 2021)

These are the first stable versions released after Python 3.9 came out on October 5, 2020. Since Python 3.8 is no longer maintained, setting these minimums helps ensure PyTorch won't be installed alongside unexpectedly old versions of these packages.

Tested with these versions locally to make sure they don't break anything. Adding CI for lower-bound testing could be a follow up later if need.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/158565
Approved by: https://github.com/janeyx99

setup.py

@@ -1233,9 +1233,9 @@ def main() -> None:
         "typing-extensions>=4.10.0",
         'setuptools ; python_version >= "3.12"',
         "sympy>=1.13.3",
-        "networkx",
+        "networkx>=2.5.1",
         "jinja2",
-        "fsspec",
+        "fsspec>=0.8.5",
     ]
     if BUILD_PYTHON_ONLY:
         install_requires += [f"{LIBTORCH_PKG_NAME}=={TORCH_VERSION}"]