The author means making compute time on the hardware available to run CI builds on their service. If you care about porting your software to RISC-V enough to want to test that software there, hardware is probably a more accurate harness than qemu.
According to the Handbook. They currently support
Alpha, AMD64, ARM, ARM64 HPPA/PA-RISC, IA64, MIPS, PPC, PPC64, SPARC and x86 (i486 and i686)
[1] Or we were up to yesterday when we had a hardware failure (on an Intel machine) so our build system is currently down. Four days before Christmas, so the worst possible time ...