Add checkout step

Author: magnmaeh

.github/workflows/memory.yml

@@ -18,6 +18,10 @@ jobs:
     name: Report memory usage
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
       - name: Generate memory usage report (current branch)
         uses: ./.github/actions/memory-report.yml
         with: