[client-python] chore(deps): update codecov/codecov-action action to v6

Author: renovate[bot]

.github/workflows/coverage.yml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Upload coverage to Codecov
         if: ${{ !cancelled() && hashFiles('coverage.xml') != '' }}
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           flags: connectors