Update msbuild reference package to get clean on scanners

[marcpopMSFT]

Update msbuild reference package to get clean on scanners

[marcpopMSFT]

@jaredpar per our recent meeting, I filed this issue. I went and double checked and unfortunately, 7.0.4xx and 8.0.1xx are being flagged as well and your reference version of msbuild there is 16.10 which is harder to upgrade (as they don't have an available 16.10 with the fixes).

[marcpopMSFT]

We did a scan of 8.0.3xx previews and found this one as well which is being flagged: https://github.com/dotnet/roslyn/blob/release/dev17.10/src/Workspaces/Core/MSBuild.BuildHost/Microsoft.CodeAnalysis.Workspaces.MSBuild.BuildHost.csproj#L27

[ericstj]

I'm not seeing this repro when building the release/dev17.10 branch. In that case I see:

      "Microsoft.Build.Tasks.Core/17.7.2": {
        "dependencies": {
...
          "System.Security.Cryptography.Xml": "7.0.1",

Seems that was fixed by @tmat in db94f71