Update codecov/codecov-action action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -101,7 +101,7 @@ jobs:
 
       - name: Upload coverage reports
         if: matrix.python-version == '3.11'
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           file: ./coverage.xml
           fail_ci_if_error: false