Updated the mirrors with:
reflector -c ‘United Kingdom’ -a 12 --sort rate --save /etc/pacman.d/mirrorlist
…and now have mirror:
https://lon.mirror.rackspace.com/archlinux/$repo/os/$arch
After a ‘sudo pacman -Syyu’ I now can install openssl-1.1 with:
sudo pacman -S openssl-1.1
…and thus php -v reports correctly. I’m detailing this in case someone trips over the same thing. Thanks for your help 