SecretCache doesn't support virtual threads in JDK 22/23 Linux

[InforBG]

Describe the bug
When starting the application service, the program will need to get many secrets from AWS SecretsManager.
To improve the performance, the program will load all secrets in a thread pool.
The issue is found when creating the ExecutorService instance with Executors.newVirtualThreadPerTaskExecutor() with JDK 22/23 Linux. When the number of virtual threads >=8, all threads hang for a long time (>30 seconds).

Tested following cases and they all work fine:

• the number of virtual threads <8;
• change to use Executors.newFixedThreadPool(20) with JDK 22/23 Linux;
• All Windows JDK 21/22/23 work fine with the virtual threads.
• Linux JDK 21 (openjdk-21.0.2_linux-x64_bin.tar.gz) works fine.

To Reproduce
Steps to reproduce:
Run the program as below:

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import com.amazonaws.secretsmanager.caching.SecretCache;

public class AWSSecretCacheXTest {

	private static final FormattingLogger LOG = FormattingLogger.getLogger(AWSSecretCacheXTest.class);

	public static void main(String[] args) {
		final SecretCache cache = new SecretCache();

		// Note: the problem can be reproduced when the number of secrets >= 8.
		List<String> secretKeys = getSecretKeys();

		// The virtual thread has problem in JDK 22/23 Linux.
		var executor = Executors.newVirtualThreadPerTaskExecutor();
		// var executor = Executors.newFixedThreadPool(20); // this works fine in JDK 22/23 Linux
		try {
			for (String secretKey : secretKeys) {
				executor.submit(() -> {
					try {
						cache.getSecretString(secretKey);
					} catch (Throwable e) {
						LOG.error("Failed to get secret key '%s'.", e, secretKey);
					}
				});
			}
		} finally {
			executor.shutdown();
			try {
				if (!executor.awaitTermination(20, TimeUnit.SECONDS)) {
					executor.shutdownNow();
				}
			} catch (InterruptedException e) {
				executor.shutdownNow();
			}
		}
	}

	static List<String> getSecretKeys() {
		List<String> secretKeys = new ArrayList<>();
		secretKeys.add("secret01");
		secretKeys.add("secret02");
		// ...
		secretKeys.add("secret09");
		return secretKeys;
	}
}

Expected behavior
The SecretCache.getSecretString() method should work when using virtual threads and JDK 22/23 Linux.

Environment

OS: amazonlinux:2,
Java Version: JDK 22/23 Linux, (amazon-corretto-23.0.0.37.1-linux-x64.tar.gz, openjdk-23_linux-x64_bin.tar.gz and openjdk-22.0.2_linux-x64_bin.tar.gz)
AWS SDK version: latest version 2.28.6.
aws-secretsmanager-caching-java version: 2.0.0.

Additional context
N/A