As a temporary solution I added sort of workaround to /etc/portage/package.accept_keywords/dolphin to emerge 25.04.3 dolphin over my setup.
Not very smart solution, but it works for me.
=kde-apps/dolphin-25.04.3 ~amd64
=kde-apps/thumbnailers-25.04.3 ~amd64
=kde-apps/baloo-widgets-25.04.3 ~amd64 ...