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

Author: michaelnebel

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

@@ -281,8 +281,16 @@ 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}";
 
+                        var environment = new Dictionary<string, string>
+                        {
+                            // From .NET 11 and onwards, the installation script uses tar by default, which we want to skip on Windows.
+                            // We still want to download the .zip archive. Otherwise an error occur in https://dot.net/v1/dotnet-install.ps1
+                            // when the archive is extracted.
+                            // We might be able to remove this restriction in the future.
+                            {"DOTNET_INSTALL_SKIP_TAR", "1"}
+                        };
                         BuildScript GetInstall(string pwsh) =>
-                            new CommandBuilder(actions).
+                            new CommandBuilder(actions, environment: environment).
                             RunCommand(pwsh).
                             Argument("-NoProfile").
                             Argument("-ExecutionPolicy").