Support aarch64 / arm64v8

[klowd92]

When i try to build a docker-compose.yml i get an error:

ben@BENCHRO-LT-IL:/tmp/balena-mdns-publisher$ balena build -d raspberrypi4-64 -A aarch64 --debug
[debug] new argv=[/home/ben/balena/balena-cli/balena,/snapshot/balena-cli/bin/balena,build,-d,raspberrypi4-64,-A,aarch64] length=7
[debug] Deprecation check: 0.32323 days since last npm registry query for next major version release date.
[debug] Will not query the registry again until at least 7 days have passed.
[Debug] Parsing input...
[Debug] Loading project...
[Debug] Resolving project...
[Debug] docker-compose.yml file found at "/tmp/balena-mdns-publisher"
[Debug] Creating project...
[Build] Building services...
[Build] balena-mdns-publisher Preparing...
[Info] Building for aarch64/raspberrypi4-64
[debug] Event tracking error: Timeout awaiting 'response' for 0ms
[Debug] Found build tasks:
[Debug] balena-mdns-publisher: image pull [balena/balena-mdns-publisher:master]
[Debug] Resolving services with [raspberrypi4-64|aarch64]
[Debug] Found project types:
[Debug] balena-mdns-publisher: External image
[Debug] Prepared tasks; building...
[Debug] balena-mdns-publisher: Using platform option for build: linux/arm64/v8
[Build] balena-mdns-publisher master: Pulling from balena/balena-mdns-publisher
[Build] Built 1 service in 0:03
[Error] Build failed.
no matching manifest for linux/arm64/v8 in the manifest list entries

[klowd92]

I have managed to build with:
balena build --deviceType raspberrypi4-64 --arch arm64v8

This should be ok, instead of aarch64