chore(deps): update codecov/codecov-action action to v6 (#256)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -55,7 +55,7 @@ jobs:
         shell: bash
       - run: uv run pytest
         shell: bash
-      - uses: codecov/codecov-action@75cd11691c0faa626561e295848008c8a7dddffe # v5
+      - uses: codecov/codecov-action@57e3a136b779b570ffcdbf80b3bdc90e7fab3de2 # v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}