Revert "[ci] Re-enable to push to dotnet9 feed (dotnet#8950)"

This reverts commit a0b7aad.

Author: jonathanpeppers

build-tools/automation/azure-pipelines.yaml

@@ -537,15 +537,6 @@ extends:
         variables:
         - ${{ if eq(variables['MicroBuildSignType'], 'Real') }}:
           - group: Publish-Build-Assets
-        templateContext:
-          outputs:
-          - output: nuget
-            condition: and(succeeded(), eq('${{ parameters.pushXAPackagesToMaestro }}', 'true'))
-            useDotNetTask: false # The default is false to use the NuGetCommand task. Set to true to use the DotNetCoreCLI task to publish packages.
-            packagesToPush: $(Build.StagingDirectory)\nuget-signed\*.nupkg
-            packageParentPath: $(Build.StagingDirectory)\nuget-signed
-            nuGetFeedType: external
-            publishFeedCredentials: $(DotNetFeedCredential)
         steps:
         - checkout: self