Add support for Visual Studio 2026 (VS 18)

[teobugslayer]

This is the Visual Studio version that supports .NET 10, so I need to use it.

But it breaks building Zed on Windows with the following error:

 CMAKE = Some("cmake")

  --- stderr

  thread 'main' panicked at C:\Users\Redacted\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\cmake-0.1.54\src\lib.rs:970:25:


  unsupported or unknown VisualStudio version: 18.0
  if another version is installed consider running the appropriate vcvars script before building this crate

I do not use Rust, I just try building Zed. I am not sure if the provided information is enough, let me know if you need anything more of me.

On my machine,

VisualStudioVersion=18.0

but ...

C:\Dev\zed>msbuild -ver
MSBuild version 17.15.0-preview-25421-07+49758e5ba for .NET Framework
17.15.0.42107

So, I think VS 2026 breaks the assumption that VS version and MSBuild versions are the same.