Bump codecov/codecov-action from 5 to 6 (#184)

Author: dependabot[bot]

.github/workflows/coverage.yml

@@ -60,7 +60,7 @@ jobs:
           TEST_HOST: ssh://test-user@localhost:2222
           XDG_RUNTIME_DIR: /tmp
       - name: Upload to codecov.io
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           fail_ci_if_error: true
     services: