Skip some permissions checks on Cygwin

Andrew Dunstan <andrew@dunslane.net>

Commit: ca947649208ce7343c54c8f92e67ea9274be812c
Author: Andrew Dunstan <andrew@dunslane.net>
Date: 2024-06-13T12:10:16Z
Releases: 12.20
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