You can't determine a build download link from its version alone anymore:
For example, the format is no longer :
https://dl.dolphin-emu.org/builds/dolphin-master-[version]-[build]-[arch].7z
But is instead :
https://dl.dolphin-emu.org/builds/[two random hex digits]/[two random hex digits]/dolphin-master-[version]-[build]-[arch].7z