Update dependencies from https://github.com/microsoft/testfx build 20251006.4

On relative base path root
Microsoft.Testing.Platform From Version 1.9.0-preview.25479.5 -> To Version 2.0.0-preview.25506.4
MSTest From Version 3.11.0-preview.25479.5 -> To Version 4.0.0-preview.25506.4

Author: dotnet-maestro[bot]

NuGet.config

@@ -4,7 +4,6 @@
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
     <!--  Begin: Package sources from microsoft-testfx -->
-    <add key="darc-pub-microsoft-testfx-2bec154" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-microsoft-testfx-2bec1546/nuget/v3/index.json" />
     <!--  End: Package sources from microsoft-testfx -->
     <!--  Begin: Package sources from dotnet-aspire -->
     <!--  End: Package sources from dotnet-aspire -->

eng/Version.Details.props

@@ -140,8 +140,8 @@ This file should be imported by eng/Versions.props
     <!-- dotnet/core-setup dependencies -->
     <NETStandardLibraryRefPackageVersion>2.1.0</NETStandardLibraryRefPackageVersion>
     <!-- microsoft/testfx dependencies -->
-    <MicrosoftTestingPlatformPackageVersion>2.0.0</MicrosoftTestingPlatformPackageVersion>
-    <MSTestPackageVersion>3.11.0-preview.25501.8</MSTestPackageVersion>
+    <MicrosoftTestingPlatformPackageVersion>2.0.0-preview.25506.4</MicrosoftTestingPlatformPackageVersion>
+    <MSTestPackageVersion>4.0.0-preview.25506.4</MSTestPackageVersion>
   </PropertyGroup>
   <!--Property group for alternate package version names-->
   <PropertyGroup>

eng/Version.Details.xml

@@ -553,13 +553,13 @@
       <Uri>https://github.com/dotnet/dotnet</Uri>
       <Sha>6befeceeaece5c9cb9730878aeaf4667f7c29b70</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Testing.Platform" Version="2.0.0">
+    <Dependency Name="Microsoft.Testing.Platform" Version="2.0.0-preview.25506.4">
       <Uri>https://github.com/microsoft/testfx</Uri>
-      <Sha>2bec15462381649ff4b770577e7b8b3bbba5ea12</Sha>
+      <Sha>29d484249f3bd0b1a60c8164b4d97aec0f2e4943</Sha>
     </Dependency>
-    <Dependency Name="MSTest" Version="3.11.0-preview.25501.8">
+    <Dependency Name="MSTest" Version="4.0.0-preview.25506.4">
       <Uri>https://github.com/microsoft/testfx</Uri>
-      <Sha>a4d4392703e56994925d8fa625219b11e6cd4837</Sha>
+      <Sha>29d484249f3bd0b1a60c8164b4d97aec0f2e4943</Sha>
     </Dependency>
     <Dependency Name="Microsoft.Extensions.Configuration.Ini" Version="10.0.0-rc.1.25479.108">
       <Uri>https://github.com/dotnet/dotnet</Uri>