Revert "[DCP] Makes fsspec public (#121508)"
This reverts commit d482614fec5fb9bccb49bf4ee4ab561e872c0f50.
Reverted https://github.com/pytorch/pytorch/pull/121508 on behalf of https://github.com/osalpekar due to this causes torchrec tests to fail internally with this error: ModuleNotFoundError: No module named 'fsspec'. see [D54779117](https://www.internalfb.com/diff/D54779117) ([comment](https://github.com/pytorch/pytorch/pull/121508#issuecomment-1992137831))
