This package does not support Python 3.12. Please test it with Python 3.12 as a matter of urgency as the default will change in early June, as per message on gentoo-dev: https://www.mail-archive.com/gentoo-dev@lists.gentoo.org/msg99104.html. Please check the information provided in the tracker. Ask in #gentoo-python on IRC if need any help.
*** Bug 931640 has been marked as a duplicate of this bug. ***
I could replicate this bug. I have my own overlay and I just added 12 on ebuild PYTHON_COMPAT=( python3_{9..12} )
This was fixed in commit 8aa66e12a4de82405030ac7dfab0091f3a3800a5