Revert "Merge pull request #26764 from dotnet/marcpopMSFT-changenugetcacheconfig"

This reverts commit ddde088, reversing
changes made to 72bb603.

Author: marcpopMSFT

build/RunTestsOnHelix.cmd

@@ -29,4 +29,6 @@ REM call dotnet new so the first run message doesn't interfere with the first te
 dotnet new --debug:ephemeral-hive
 REM avoid potetial cocurrency issues when nuget is creating nuget.config
 dotnet nuget list source
-dir /B %DOTNET_ROOT%\.nuget
+REM We downloaded a special zip of files to the .nuget folder so add that as a source
+dotnet nuget add source %DOTNET_ROOT%\.nuget
+dir /B %DOTNET_ROOT%\.nuget

src/Tests/HelixTasks/SDKCustomCreateXUnitWorkItemsWithTestExclusion.cs

@@ -130,9 +130,6 @@ private async Task<List<ITaskItem>> PrepareWorkItem(ITaskItem xunitProject)
 
             string msbuildAdditionalSdkResolverFolder = netFramework ? "-e DOTNET_SDK_TEST_MSBUILDSDKRESOLVER_FOLDER=%HELIX_CORRELATION_PAYLOAD%\\r" : IsPosixShell ? "" : "-msbuildAdditionalSdkResolverFolder %HELIX_CORRELATION_PAYLOAD%\\r";
 
-            // We want to add a nuget cache for predownloaded runtime packages but this appears to break the packageinstall tests. For now only enable on windows
-            string localNugetCache = IsPosixShell || assemblyName.Contains("Microsoft.DotNet.PackageInstall.Tests") ? "" : "dotnet nuget add source %DOTNET_ROOT%\\.nuget & ";
-
             var scheduler = new AssemblyScheduler(methodLimit: 32);
             var assemblyPartitionInfos = scheduler.Schedule(targetPath, netFramework: netFramework);
 
@@ -146,8 +143,6 @@ private async Task<List<ITaskItem>> PrepareWorkItem(ITaskItem xunitProject)
                     command = $"{driver} test {assemblyName} {testExecutionDirectory} {msbuildAdditionalSdkResolverFolder} {(XUnitArguments != null ? " " + XUnitArguments : "")} --results-directory .\\ --logger trx {testFilter}";
                 }
 
-                command = localNugetCache + command;
-
                 Log.LogMessage($"Creating work item with properties Identity: {assemblyName}, PayloadDirectory: {publishDirectory}, Command: {command}");
 
                 TimeSpan timeout = TimeSpan.FromMinutes(5);