Update branding to 2.1.39

[wtgodbe]

I couldn't find any runtime/extensions packages that obviously needed updates, though we could update the aspnetcore.app version from 2.1.27 to 2.1.30

[dougbu]

All pinned dependencies need to be updated to match the latest published versions e.g. https://www.nuget.org/packages/Microsoft.Extensions.Caching.Memory/2.1.23.

May need to move some dependencies from the "Pinned" group to "Auto" if something in CoreFx or extensions is building for 2.1.38. May also need to update $(MicrosoftNETCoreApp21PackageVersion) if nothing below efcore will build for the next release.

There are no ASP.NET dependencies in this repo except Microsoft.AspNetCore.Hosting.WebHostBuilderFactory.Sources. That version should be 2.1.9 (matching the latest in https://dotnetmygetlegacy.blob.core.windows.net/dotnet-core/index.json) or (likely better) 2.1.17-servicing-31324 (matching the latest in https://pkgs.dev.azure.com/dnceng/public/_packaging/myget-legacy/nuget/v3/index.json).

[wtgodbe]

All pinned dependencies need to be updated to match the latest published versions e.g. https://www.nuget.org/packages/Microsoft.Extensions.Caching.Memory/2.1.23.

That one's already up to date here, but looks like MicrosoftAspNetCoreHostingWebHostBuilderFactorySourcesPackageVersion and MicrosoftNETCoreApp21PackageVersion should be updated