Fix F3 sidecar FFI build for aarch64 on MacOS

[hanabi1224]

And re-enable Go FFI build for aarch64 on MacOS. As follow up of #4764

fn is_sidecar_ffi_enabled() -> bool {
    // Note: arm64 is disabled for now as cross-compilation is not yet supported in rust2go
    // and it's reported rust2go build does not work on arm64 MacOS
    if cfg!(target_arch = "x86_64") {
        // Opt-out building the F3 sidecar staticlib
        match std::env::var("FOREST_F3_SIDECAR_FFI_BUILD_OPT_OUT") {
            Ok(value) => !matches!(value.to_lowercase().as_str(), "1" | "true"),
            _ => true,
        }
    } else {
        false
    }
}

[ruseinov]

Taking this on after talking to @elmattic