try using submodules: true

.github/workflows/build_and_test.yml

@@ -28,6 +28,7 @@ jobs:
     - uses: actions/checkout@v4
       with:
         fetch-depth: '0'
+        submodules: true
     - run: git fetch --depth=1 origin +refs/tags/*:refs/tags/* +refs/heads/*:refs/remotes/origin/*
     - name: Set up Python 3.10
       uses: actions/setup-python@v5