For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:games/openSUSE_Leap_15.6/home:rhabacker:branches:games.repo
zypper refresh
zypper install spirv-headers
For openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:games/openSUSE_Leap_15.5/home:rhabacker:branches:games.repo
zypper refresh
zypper install spirv-headers
For SLE 15 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:rhabacker:branches:games/SLE_15_SP3/home:rhabacker:branches:games.repo
zypper refresh
zypper install spirv-headers