Windows Arm64 support

**Is your feature request related to a problem? Please describe.**
Currently, `dotnet sign` explicitly targets Windows x64. This presents a problem when needing to run the tool from Windows arm64 devices running dotnet, as the sign.dll cannot be loaded from that context.
> Unhandled exception. System.IO.FileLoadException: Could not load file or assembly 'sign, Version=0.9.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

With the debut of the Windows arm64 GitHub Actions runners, this is more imperative to support - otherwise we miss out on an opportunity to fully support dotnet in its entirety, especially on *ALL* Windows platforms.

**Describe the solution you'd like**
A clear and concise description of what you want to happen.
I would like to see `dotnet sign` to emit architecture specific artifacts to support running from either the x64 or arm64 Windows hosts.

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.
An alternative solution is to run the x64 dotnet binary and run the `sign.dll` from where the tool is installed.

Example)
`"c:\Program Files\dotnet\x64\dotnet.exe" %USERPROFILE%\.dotnet\tools\.store\sign\0.9.1-beta.25181.2\sign\0.9.1-beta.25181.2\tools\net8.0\any\sign.dll`

This step is obviously tedious and removes the point of calling `sign`.

**Additional context**
Include the output of sign --version.
Add any other context about the problem here.

Reference to @dlemstra who originally alerted me to this https://bsky.app/profile/dirk.lemstra.org/post/3lmxetzgdcc2c