Add ARM64 server-only CI build job
Adds an ARM64 server-only build job using foss.heptapod.net's instance runners. No client build, as FMOD Ex doesn't support ARM.
This instance will be upgraded to Heptapod 17.3.0rc1 on 2024-09-20 between 16:00 and 17:00 UTC+2
Adds an ARM64 server-only build job using foss.heptapod.net's instance runners. No client build, as FMOD Ex doesn't support ARM.