Skip some permissions checks on Cygwin

Andrew Dunstan <andrew@dunslane.net>

Commit: c38518fa978075d08d64a34e1b4504da13a81e02
Author: Andrew Dunstan <andrew@dunslane.net>
Date: 2024-06-13T11:41:49Z
Releases: 15.8
Skip some permissions checks on Cygwin

These are checks that are already skipped on other Windows systems.

Backpatch to all live branches, as appropriate.

Files