test_all: use a fresh Internet Archive item for the integration tests

The old rclone-integration-test item has accumulated years of catalog
task churn and IA now deprioritises and periodically holds its tasks,
which makes the tests wait on the server's processing tasks for a
very long time. Start again with a fresh item (created with noindex
set so the test files stay out of IA's search index).

fstest/test_all/config.yaml

@@ -211,7 +211,7 @@ backends:
    ignoretests:
      - cmd/bisync
  - backend:  "internetarchive"
-   remote:   "TestIA:rclone-integration-test"
+   remote:   "TestIA:rclone-integration-test-2"
    fastlist: true
    tests:
      - backend