Remove link to PyOxy since that project is all but dead?

The docs currently reference pyoxy/pyoxide: https://github.com/astral-sh/python-build-standalone/blob/c1991f8fc3eb8774907f0cffb93792f59079cd7a/docs/index.rst#L26

But that project is essentially dead: https://github.com/indygreg/PyOxidizer/discussions/740

Remove the reference to it in this project's docs?

Open docs/index.rst around the referenced link at line 26 and inspect the PyOxy/PyOxidizer reference. Remove that documentation reference, then verify the stale link and project name no longer appear in the relevant docs section.

Written by the indexing model from the issue text.