This issue was originally encompassed in #58445. I am moving it to this new issue for better clarity and tracking of the work that needs to be done.

Currently, aspnetcore builds on mac & linux, then shuttles those bits to Windows to sign using Arcade's SignTool. Now that there is support for signing directly on mac & linux with SignTool, aspnetcore builds should sign the artifacts on the build machines (eg if an artifact was built on mac, we should/can now sign it on a mac). In other words, we should alter aspnetcore to be more 'vertical'.