3.1.102 release broke build using Microsoft.Win32

# 3.1.102 release broke build working on 3.1.101

I use dot.net sdk image to build my app inside Docker, using image tagged as `mcr.microsoft.com/dotnet/core/sdk:3.1-alpine`
My application has `TargetFramework` set to `netcoreapp3.1`
Previous version used for build was 3.1.101 and code using type `Registry` from assembly `Microsoft.Win32` was build without any problems on Linux containers, targeting runtimes `win10-x64` and `osx.10.11-x64`.

Today our build server downloaded new version of image - 3.1.102 and now build is broken for both runtimes mentioned earlier.

Build error:
```
Infrastructure/Networking/INetSettings.cs(32,37):
error CS0103: The name 'Registry' does not exist in the current context
```

Sticking my Docker build environment to image `mcr.microsoft.com/dotnet/core/sdk:3.1.101-alpine` solves the problem, but I don't see anything in Release Notes for version 3.1.102 which I should care about, I think it's may be a bug.