emulators/virtualbox-ose*-71,www/phpvirtualbox-71: Deprecate with expiration date 2026-12-31

"VirtualBox 7.1.x is no longer supported!"
https://www.virtualbox.org/wiki/Changelog-7.1

Upstream EOL reaches on 2025-04-15, use emulators/virtualbox-ose*-72
instead.
Set expiration date to 2026-12-31.

Sponsored by: UNIS Labs
MFH: 2026Q2

(cherry picked from commit c1b7acedbae9694bc4211bdd5d2f48dd1309d581)