Bump codecov up to v6

Author: iskandergaba

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         run: uv run pytest --cov
 
       - name: Upload results to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           token: "${{ secrets.CODECOV_TOKEN }}"
           disable_telem: true