Improve IT cluster readiness diagnostics

[Caideyipi]

Description

This PR improves integration-test cluster readiness handling and raises the pipe workflow cluster-ready retry window.

• make the default cluster ready retry count configurable through integrationTest.clusterReadyRetryCount, while keeping the framework default at 30
• set -DintegrationTest.clusterReadyRetryCount=90 for all Maven IT invocations in .github/workflows/pipe-it.yml
• include cluster readiness failure details in the final assertion message, including node sizes, last node status, process status, last exception, and log directories
• dump node jstacks when cluster status or JDBC readiness checks exhaust retries
• record per-DataNode JDBC connection failures during readiness checks
• clear MultiEnvFactory environments before creating a new multi-env set to avoid static list growth across test methods

Tests

• mvn spotless:apply -pl integration-test -P with-integration-tests -DskipTests
• mvn -Ddevelocity.off=true spotless:check -pl integration-test -P with-integration-tests -DskipTests
• git diff --check -- integration-test/src/main/java/org/apache/iotdb/it/env/cluster/env/AbstractEnv.java integration-test/src/main/java/org/apache/iotdb/it/env/MultiEnvFactory.java
• git diff --check -- .github/workflows/pipe-it.yml
• mvn -Ddevelocity.off=true compile -pl integration-test -P with-integration-tests -DskipTests reached BUILD SUCCESS; the local JVM then exited with a native memory/pagefile error after build completion