⚙️ config(ci): Fix codecov code coverage upload issue.

See codecov/codecov-action#1801.

Author: make-github-pseudonymous-again

.github/workflows/use-tests.yml

@@ -76,6 +76,11 @@ jobs:
     timeout-minutes: 1
 
     steps:
+      - name: Checkout 🛎️
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
       - name: Load coverage data 💽
         uses: actions/download-artifact@v4
         with: