C#: Use the zip archive on windows runners, when downloading and installing .NET.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs

@@ -282,7 +282,7 @@ private static BuildScript DownloadDotNetVersion(IBuildActions actions, ILogger
                         var psCommand = $"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; &([scriptblock]::Create((Invoke-WebRequest -UseBasicParsing 'https://dot.net/v1/dotnet-install.ps1'))) -Version {version} -InstallDir {path}";
 
                         BuildScript GetInstall(string pwsh) =>
-                            new CommandBuilder(actions).
+                            new CommandBuilder(actions, environment: MinimalEnvironment).
                             RunCommand(pwsh).
                             Argument("-NoProfile").
                             Argument("-ExecutionPolicy").

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/IDotNetCliInvoker.cs

@@ -23,7 +23,8 @@ internal interface IDotNetCliInvoker
             {"DOTNET_CLI_UI_LANGUAGE", "en"},
             {"MSBUILDDISABLENODEREUSE", "1"},
             {"DOTNET_SKIP_FIRST_TIME_EXPERIENCE", "true"},
-            {"DOTNET_CLI_TELEMETRY_OPTOUT", "1"}
+            {"DOTNET_CLI_TELEMETRY_OPTOUT", "1"},
+            {"DOTNET_INSTALL_SKIP_TAR", "1"}
         });
 
         /// <summary>