When you remove gsettings-desktop-schemas and gsettings-system-schemas, can you check if those 5 files are also removed?
sudo pacman -Rdd gsettings-desktop-schemas gsettings-system-schemas
If not, remove them manually
sudo rm /usr/share/glib-2.0/schemas/org.gnome.desktop.a11y.magnifier.gschema.xml
sudo rm /usr/share/glib-2.0/schemas/org.gnome.desktop.interface.gschema.xml
sudo rm /usr/share/glib-2.0/schemas/org.gnome.desktop.peripherals.gschema.xml
sudo rm /usr/share/glib-2.0/schemas/org.gnome.desktop.privacy.gschema.xml
sudo rm /usr/share/glib-2.0/schemas/org.gnome.system.location.gschema.xml
then reinstall those removed packages
sudo pacman -S gsettings-desktop-schemas