Fix CI workflow condition for Windows OS detection

- Updated the condition in the CI workflow configuration to correctly check for Windows OS using `matrix.os` instead of `matrix.config.os`, ensuring proper execution of the MSVC development command.

Author: sean-parent

templates/.github/workflows/ci.yml.in

@@ -36,7 +36,7 @@ jobs:
 
     steps:
       - uses: @CI_ACTION_CHECKOUT@
-      - if: ${{ startsWith(matrix.config.os, 'windows') }}
+      - if: ${{ startsWith(matrix.os, 'windows') }}
         uses: @CI_ACTION_MSVC_DEV_CMD@
 
       - name: Configure CMake