ci: Try to activate cppad codegen binding with clang-cl

.github/workflows/ci-windows.yml

@@ -10,6 +10,9 @@ env:
 jobs:
   build:
     runs-on: ${{ matrix.os }}
+    env:
+      BUILD_CPPAD_CODEGEN: OFF
+
     strategy:
       fail-fast: true
       matrix:
@@ -29,6 +32,13 @@ jobs:
         python-version: 3.8
         auto-activate-base: false
 
+    - name: Setup cppad codegen
+      if: contains(matrix.compiler, 'clang')
+      shell: cmd /C CALL {0}
+      run: |
+        conda install cppadcodegen
+        echo "BUILD_CPPAD_CODEGEN=ON" >> "$GITHUB_ENV"
+
     - name: Build PyCppAD
       shell: cmd /C CALL {0}
       env:
@@ -46,7 +56,7 @@ jobs:
           -DCMAKE_INSTALL_PREFIX=%CONDA_PREFIX%\Library ^
           -DPYTHON_SITELIB=%CONDA_PREFIX%\Lib\site-packages ^
           -DPYTHON_EXECUTABLE=%CONDA_PREFIX%\python.exe ^
-          -DBUILD_WITH_CPPAD_CODEGEN_BINDINGS=OFF ^
+          -DBUILD_WITH_CPPAD_CODEGEN_BINDINGS=%BUILD_CPPAD_CODEGEN% ^
           ..
 
         :: Build