Manually update the dependencies.props and move S.P.Corelib to use LangVersion=8...

Manually update the dependencies.props and move S.P.Corelib to use LangVersion=8.0 (dotnet/coreclr#22452)

* Update BuildTools to preview1-03713-01 (master)

* Updating CoreCLR to use LangVersion=8.0

* Moving the Windows scripts to default to `dotnet msbuild` for managed components

* Setting UseSharedCompilation=true

* Changing some additional callsites that were using msbuild to use dotnet msbuild

* Revert packages.builds to use Desktop msbuild on Windows

* Fixing runtest.cmd to always set DotNetCli

Commit migrated from https://github.com/dotnet/coreclr/commit/cd9831cd00408db60364f367756de296852467ae