integTestRemote can run multiple forks against a shared remote cluster, so @After cleanup in ODFERestTestCase deletes .opendistro-anomaly-detectors while other tests are mid‑request, causing 404s in SecureADRestIT and other REST ITs.
When tests.rest.cluster is set, this PR forces integTestRemote to run serially (maxParallelForks=1, forkEvery=0) to avoid cross‑test index wipe races.

Signed-off-by: kaituo <kaituo@amazon.com>