[Feature]: build for freebsd-arm64

Feature Summary

Please add -freebsd-arm64 to the standard build images

What problem does this feature solve?

I cannot run miniflux under freebsd on arm64 (raspberry pi) hardware.

Proposed Solution

Please add -freebsd-arm64 to the standard builds that are available from miniflux.app/releases/...

Alternatives Considered

No response

Additional Context

I am progressively moving my servers from linux (ubuntu server) to freebsd - it's much more convenient and light-weight than the normal linux server distributions :)

Checklist

• I have searched existing issues to ensure this feature hasn't been requested before.
• I understand that feature requests are not guaranteed to be implemented.
• I agree to follow the project's contribution guidelines.