[8.0] Remove Windows 8.1 from test queues

Backport of #112056 and #111462

Author: akoeplinger

eng/pipelines/libraries/helix-queues-setup.yml

@@ -133,7 +133,6 @@ jobs:
             - ${{ if ne(parameters.jobParameters.testScope, 'outerloop') }}:
               - (Windows.10.Amd64.ServerRS5.Open)windows.10.amd64.serverrs5.open@mcr.microsoft.com/dotnet-buildtools/prereqs:windowsservercore-ltsc2019-helix-amd64
           - ${{ if or(ne(parameters.jobParameters.isExtraPlatforms, true), eq(parameters.jobParameters.includeAllPlatforms, true)) }}:
-            - Windows.81.Amd64.Open
             - Windows.Amd64.Server2022.Open
             - Windows.11.Amd64.Client.Open
             - ${{ if eq(parameters.jobParameters.testScope, 'outerloop') }}: