Update sanitizer.yml

Author: sequoiar

.github/workflows/sanitizer.yml

@@ -17,6 +17,8 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v2
+      - name: Checkout submodules
+        run: git submodule update --init --recursive
       - name: Setup
         run: |
           sudo apt-get install ninja-build