github: Fetch submodule recursively

Author: bt

.github/workflows/cmake-single-platform.yml

@@ -21,6 +21,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+      submodules: recursive
 
     - name: Configure CMake
       # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.