Used the wrong image names (they were the helix names instead of the AzDO agent image names).

Author: MiYanni

eng/pipelines/official.yml

@@ -126,7 +126,7 @@ variables:
 # Variables used: DncEngInternalBuildPool
 - template: /eng/common/templates-official/variables/pool-providers.yml@source
 - name: AgentImageInternal
-  value: windows.amd64.vs2026.pre.scout
+  value: windows.vs2026preview.scout.amd64
 ############### ARCADE ###############
 # Both this (used in Arcade for the MicroBuildSigningPlugin) and DotNetSignType (used in Arcade in Sign.proj) are necessary to set the sign type.
 # https://github.com/dotnet/arcade/blob/ccae251ef033746eb0213329953f5e3c1687693b/Documentation/ArcadeSdk.md#common-steps-in-azure-devops-pipeline

eng/pipelines/templates/variables/workload-public.yml

@@ -1,6 +1,6 @@
 variables:
 - name: AgentImagePublic
-  value: windows.amd64.vs2026.pre.scout.open
+  value: windows.vs2026preview.scout.amd64.open
 - name: _SignType
   value: test
 - name: _TeamName