Add macos universal release binary

[dflems]

trafficstars

We try and use universal binaries in our workflows wherever we can so we don't have to have special logic to download the right tool depending on whether the mac running the job is an Apple Silicon mac or an Intel mac. On macOS it's fairly easy to create universal binaries using the lipo command:

xcrun lipo -create \
  buildifier-darwin-amd64 \
  buildifier-darwin-arm64 \
  -output buildifier-darwin-universal

Would it be possible to add a universal binary for each official release on the Github releases page? I'm not sure in what context the release scripts are run or on which kinds of machines so I'm not sure of the best place to add this. Would be happy to try this myself.

[dflems]

This has been open for the better part of a year. Not sure who to ping to take a look at this. @vladmos maybe?