XDPH doesn't need ** keyword, it means portage will pull in the latest git version of XDPH available, which at the time of writing the wiki may have been required, but is not necessary now.
* Update Gentoo installation instructions for XDPH
* Changed the suggested overlay from useless-overlay to GURU.
* Bumped qt versions in the docs from 6.4.0 to 6.4.3 since 6.4.0 is not available anymore.
* Remove dependency on specific Qt versions for the Gentoo instructions
Now, the instructions suggest to just unmask the whole package instead of specific versions.