Update codecov/codecov-action action to v6

Author: renovate[bot]

.github/workflows/ci-cd.yml

@@ -39,7 +39,7 @@ jobs:
           poetry run pytest -v --cov=sqlite_ml --cov=tests --cov-branch --cov-report=term-missing tests
           poetry run coverage xml
       - name: Publish code coverage to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           file: ./coverage.xml