These are probably old and not needed anymore.
They may be remnants from you using pamac with sudo in the past.
ls -hl /var/lib/pacman/sync/
There likely are no files there.
Check:
ls -hl /var/lib/pacman/sync/download*
I don’t have such directories present here - but I don’t have anything from AUR installed.
remove these directories after you have convinced yourself that there is nothing there that you want:
sudo rm -rf /var/lib/pacman/sync/download*
to get the command output in english, prepend
LANG=C