I needed this because I did not want to have a dependency on .NET 6 anymore.
I am providing this to save a bit of your time.
Use it at your own risk. If you don't trust me (which I would understand), you can also fork the main repository (https://github.com/vcsjones/AzureSignTool), and apply those changes:
.NET 8 upgrade: vcsjones@f7f4683
Standalone executable: vcsjones@a39b8ac
Then you can do this:
dotnet publish -r <RUNTIME_IDENTIFIER>
<RUNTIME_IDENTIFIER>:
win-x64(default)win-x86win-arm64