Support ARM Linux

ARM Linux support would be nice. Now with Asahi Linux growing quite quickly it would make sense to support it.

I support this.
I have been a long time user of Mailspring - even a paying customer for a couple of years.
However, I have switched to linux asahi on a MBA 15" 2022.
I was able to build mailspring for the architecture, however this doesn’t include Mailsync, which doesn’t build. When I run mailspring, I get a popup saying
“Mailspring could not find the mailsync process. If you’re building Mailspring from source, make sure mailsync.tar.gz has been downloaded and unpacked in your working copy.”
Indeed a mailsync linux arm is not amongst the offered architectures/tarballs. I have also try to built it (as mailsync is also open source, thanks) but did not succeed.

Any chance to get a linux arm64 mailsync? Thanks for considering.