First, wait for that pull request to actually show "merged" instead of open, then, wait for a release of xwayland, you can find those here: https://gitlab.freedesktop.org/xorg/xserver/-/tags
Once that's been released, note the version number of the version of xwayland that has explicit sync
https://packages.fedoraproject.org/pkgs/xorg-x11-server-Xwayland/xorg-x11-server-Xwayland/
then look here and see if the version number matches or is greater than it.
edit: woo it's merged.
yeah i'm doing this because i'm anal not because there's a good reason to.