hello and welcome ... how quiet is in the forum today ... that package is already moved to archive, but repo data is not updated ... so, you should wait (not so long, I think), or download that package from
here and try to install it manualy after installation proces stop, using
# arch-chroot /mnt
# pacman -U path_to_package_bluez-libs-5.52-2-x86_64.pkg.tar.xz
and restart installation ...