gh-89745: Remove dead realpath branch in getpath.c

[pelson]

The readlink code before is always taking precedence, and I don't know of a platform which has realpath but not readlink.

Note that this is a bit of a speculative change identified when tackling another getpath[.py] issue - I have no broad knowledge of platforms to be 100% certain that realpath without readlink isn't a thing.

• Issue: Rewrite getpath.c in Python #89745

[pelson]

It looks like this came in part in 99fcf15#diff-ad0a6e4fd367f158f5af826b512704cef7808813c3a3a474f9d8a10b5ef75e45.

[pelson]

@FFY00 and @zooba - is this a worthwhile change? If so, I'm happy to open up an issue, rebase, etc.

If not, I would also be happy to just close the PR.

[zooba]

I have no broad knowledge of platforms to be 100% certain that realpath without readlink isn't a thing.

Me neither. I'm not confident to remove code that I copy-pasted (I assume from posixmodule.c, possibly from fileutils.c, but I expect if it were there then I could've just called it).

[github-actions]

This PR is stale because it has been open for 30 days with no activity.

[picnixz]

Closing as we are not entirely sure it is really a dead path.