Add homebrew formula for published testing binaries

[anuraaga]

After this is merged, it should be possible to install with

brew tap elastic/ollama https://github.com/elastic/ollama # 2nd arg needed since this repo's name isn't homebrew-ollama
brew install ollama-elastic
ollama-elastic --version

I checked the tap locally on both macos and linux/amd64 - homebrew doesn't seem to support linux/arm64.

Followed this for inspiration, especially the use of prebuilt binaries. It's not idiomatic in homebrew proper to do that, but given the build is quite heavy I think this is simpler than build from source (spent a couple hours today getting ollama to build again after having updated macos to sequoia...).

https://github.com/ymtdzzz/homebrew-tap/blob/main/otel-tui.rb

[codefromthecrypt]

a little confused per "homebrew doesn't seem to support linux/arm64." should we still build?

[anuraaga]

Figured it doesn't hurt to keep it here in case brew adds support out of band later. If it's confusing, can remove it. The build won't be faster unfortunately since it's the Darwin artifact that takes quite a while.

[codefromthecrypt]

makes sense