make build more verbose

Author: mattip

.github/workflows/pybind11.yml

@@ -98,7 +98,7 @@ jobs:
         ${{ matrix.args }}
 
     - name: Build C++11
-      run: cmake --build . -j 2
+      run: cmake --build . -j 2 -vv
 
     - name: Python tests C++11
       run: cmake --build . --target pytest -j 2