[release/8.0.3xx] Update dependencies from dotnet/arcade

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/dotnet/arcade

• Subscription: 8ff8e8c7-1dbf-4468-5f69-08dc11e990e4
• Build: 20250915.1 (283246)
• Date Produced: September 15, 2025 9:50:01 PM UTC
• Commit: 4bd1c6c93b5a3b8bc864d2863469c3f2e489d0af
• Branch: release/8.0

• Updates:
  • From 8.0.0-beta.25455.3 to 8.0.0-beta.25465.1
    • Microsoft.DotNet.Arcade.Sdk
    • Microsoft.DotNet.Helix.Sdk
    • Microsoft.DotNet.SignTool
    • Microsoft.DotNet.XUnitExtensions

• Updates to .NET SDKs in root:
  • Updates tools.dotnet to 8.0.120

[SimonZhao888]

@dsplaisted the test legs failed with the following error:
NETSDK1138: Target framework 'net6.0' is no longer supported and will not receive future security updates.
Should we update <TargetFramework>net6.0</TargetFramework> in Microsoft.DotNet.ApiCompat.Tool.csproj and Microsoft.DotNet.GenAPI.Tool.csproj to a higher version?

[dsplaisted]

@dsplaisted the test legs failed with the following error: NETSDK1138: Target framework 'net6.0' is no longer supported and will not receive future security updates. Should we update <TargetFramework>net6.0</TargetFramework> in Microsoft.DotNet.ApiCompat.Tool.csproj and Microsoft.DotNet.GenAPI.Tool.csproj to a higher version?

@dotnet/area-infrastructure-libraries @baronfel @marcpopMSFT We're getting this warning (as error) when trying to compile ApiCompat and GenApi in the 8.0 branch. Should we suppress the warning? I'm not sure we'd want to retarget these tools in servicing.

[marcpopMSFT]

@dsplaisted ping @ericstj and @jeffhandley on teams. When you mentioned it earlier, I didn't realize this was in servicing. I double they are going to change the supported versions in servicing so probably we skip the EOL check.