Fix Windows pipeline image to use windows.vs2022.amd64.open (#14492)

* Fix Windows pipeline image to use windows.vs2022.amd64.open

* Use windows.vs2026preview.scout.amd64 for public pipeline Windows pool

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: joperezr

eng/pipelines/templates/public-pipeline-template.yml

@@ -86,7 +86,7 @@ stages:
 
           pool:
             name: $(DncEngPublicBuildPool)
-            demands: ImageOverride -equals 1es-windows-2022-open
+            demands: ImageOverride -equals windows.vs2026preview.scout.amd64.open
 
           variables:
             - name: _buildScript