PHP Unit tests are failing on Nightly WP builds

[jazzsequence]

See https://github.com/pantheon-systems/pantheon-advanced-page-cache/actions/runs/16008585600/job/45160868075?pr=334

Looks like there's some discrepancies in what cache tags are expected vs generated.

[jazzsequence]

@pantheon-systems/site-experience

[AnaisPantheor]

We might be looking at
https://core.trac.wordpress.org/changeset/60365 (release June 29, 2025)
https://core.trac.wordpress.org/ticket/42522
and
https://core.trac.wordpress.org/changeset/60510 (released July 25, 2025)
https://core.trac.wordpress.org/ticket/63562

WordPress Core introduced two optimizations (Tickets #63562 and #42522) to avoid unnecessary recalculations of term counts, especially when a post's status is unchanged or is a non-public status like 'draft'.

This optimization resulted in skipping the call to clean_term_cache() when a draft post with terms is saved. PAPC was relying on this call to fire a hook and purge its term cache keys, for unpublished posts, leading to tests failing because the old, stale cache entries were no longer being reliably invalidated.