How outdated themes are managed

### Enhancement Proposal

Hi team,

There is this theme https://github.com/canonical/wordpress-k8s-operator/blob/d791f593e4ee4b7604ace698ce215f22ae6d87b0/wordpress_rock/rockcraft.yaml#L273-L286

which we use in the Canonical web team for our blog page, but the theme seems to be written with an older version of PHP.
Trying to upgrade our wordpress charm to newer revisions and activating the theme, as the one we use is quite old, the wordpress app crashes (due to outdated PHP syntax used).

In the theme's code, there are some custom post types and config being set in the themes code that is essential to how our blog pages work.

How is this theme maintained?
Do we create an fixed version of the theme and replace this one?

I ask as the themes are being manages by` ~canonical-sysadmins` on launchpad.

Start with the linked rockcraft.yaml section at lines 273-286 and inspect how the referenced theme is included and maintained. Clarify the ownership and upgrade path for the outdated theme, then document whether it should be fixed in place or replaced; the issue provides no test or implementation entry point.

Written by the indexing model from the issue text.