fix: add back checkout

.github/workflows/main.yml

@@ -102,6 +102,10 @@ jobs:
     runs-on: ubuntu-latest
     container: python:latest
     steps:
+      - name: Checkout
+        uses: actions/checkout@v5.0.0
+        with:
+          submodules: "true"
       - name: Install deps
         run: |
           apt-get update && apt-get install -y git