[BUG] Reroute an index shard between nodes test is flaky

[dblock]

What is the bug?

Cluster rerouting test is flaky.

https://github.com/opensearch-project/opensearch-api-specification/actions/runs/10720682021/job/29731120869?pr=552

ERROR   cluster/reroute.yaml (/home/runner/work/opensearch-api-specification/opensearch-api-specification/tests/routing/cluster/reroute.yaml)
    ERROR   CHAPTERS
        PASSED  Shows the allocation of shards in a cluster.
            PASSED  REQUEST BODY
            PASSED  RESPONSE STATUS
            PASSED  RESPONSE PAYLOAD BODY
            PASSED  RESPONSE PAYLOAD SCHEMA
            SKIPPED RESPONSE OUTPUT VALUES
        PASSED  Shows the allocation of shards in a cluster with parameters.
            PASSED  PARAMETERS
                PASSED  dry_run
                PASSED  explain
                PASSED  metric
                PASSED  retry_failed
            PASSED  REQUEST BODY
            PASSED  RESPONSE STATUS
            PASSED  RESPONSE PAYLOAD BODY
            PASSED  RESPONSE PAYLOAD SCHEMA
            SKIPPED RESPONSE OUTPUT VALUES
        ERROR   Reroute an index shard between nodes.
            PASSED  REQUEST BODY
            ERROR   RESPONSE STATUS (Expected status 200, ...)
            SKIPPED RESPONSE PAYLOAD BODY
            SKIPPED RESPONSE PAYLOAD SCHEMA
            SKIPPED RESPONSE OUTPUT VALUES

How can one reproduce the bug?

Try the test enough times.

cd tests/routing/
docker compose up

export OPENSEARCH_PASSWORD=myStrongPassword123!
npm run test:spec--insecure -- --tests tests/routing/cluster/reroute.yaml --verbose

What is the expected behavior?

Test to pass consistently.

What is your host/environment?

GHA

Do you have any screenshots?

https://github.com/opensearch-project/opensearch-api-specification/actions/runs/10720682021/job/29731120869?pr=552