Use STL in one of MSVS CI builds

Do (almost) the same thing done in appveyor.yml to change wxUSE_STL
value in setup.h.

.github/workflows/ci_msw.yml

@@ -58,6 +58,7 @@ jobs:
           - configuration: 'DLL Release'
             platform: 'x64'
             vsversion: 2019
+            use_stl: true
 
     steps:
       - name: Checkout
@@ -65,6 +66,15 @@ jobs:
         with:
           submodules: 'recursive'
 
+      - name: Configure to use STL
+        if: matrix.use_stl
+        working-directory: include/wx/msw
+        run: |
+            $txt = Get-Content setup.h
+            Write-Output $txt |
+            %{$_ -replace "define wxUSE_STL 0", "define wxUSE_STL 1"} |
+            Set-Content setup.h
+
       - name: Add MSBuild to PATH
         uses: microsoft/setup-msbuild@v1.0.3
         with: