CI/macOS: fix second mkdir

Author: fabinsch

.github/workflows/ci-linux-osx-win-conda.yml

@@ -89,8 +89,6 @@ jobs:
       run: |
         echo $(whereis ccache)
         echo $(which ccache)
-        git submodule update --init
-        mkdir build
         cd build
         cmake .. -GNinja -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache -DCHECK_RUNTIME_MALLOC:BOOL=ON -DCMAKE_CXX_STANDARD=${{ matrix.cxx_std }} -DCMAKE_INSTALL_PREFIX=${CONDA_PREFIX} -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DBUILD_PYTHON_INTERFACE:BOOL=ON -DPYTHON_EXECUTABLE=$(which python3) -DINSTALL_DOCUMENTATION:BOOL=ON -DTEST_JULIA_INTERFACE:BOOL=ON