Providing -pp will suppress errors and fail silently

To reproduce, do the following:
1. Create a new console project with `dotnet new console`.
2. Open the `foo.csproj` or project file created by new console. Edit it to be like this:

```

Blah

Exe
net7.0
enable
enable

```

run `dotnet msbuild --pp` and observe that no error is produced and msbuild is silent, but without `--pp` it will raise an error.