### CI Link

https://gradle-enterprise.elastic.co/s/jze725jpxi7ki/console-log?task=:x-pack:plugin:security:internalClusterTest

### Repro line

./gradlew ':x-pack:plugin:security:internalClusterTest' --tests "org.elasticsearch.xpack.security.authc.pki.PkiAuthDelegationIntegTests.testDelegateThenAuthenticate" -Dtests.seed=F5EC1FEFFC2FC08B -Dtests.locale=en-GB -Dtests.timezone=SystemV/PST8PDT -Druntime.java=20

### Does it reproduce?

Yes

### Applicable branches

main

### Failure history

_No response_

### Failure excerpt

The pki integ test began failing today. Looking at the certs the test uses, they are all expired:

```
❯ openssl x509 -enddate -noout -in testClient.crt
notAfter=Jul 18 13:33:41 2023 GMT
❯ openssl x509 -enddate -noout -in testIntermediateCA.crt
notAfter=Jul 18 13:32:34 2023 GMT
❯ openssl x509 -enddate -noout -in testRootCA.crt
notAfter=Jul 18 13:32:20 2023 GMT
```
x-pack/plugin/security/src/internalClusterTest/java/org/elasticsearch/xpack/security/authc/pki/PkiAuthDelegationIntegTests.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0; you may not use this file except in compliance with the Elastic License
 * 2.0.
 */
package org.elasticsearch.xpack.security.authc.pki;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.ResponseException;
import org.elasticsearch.common.settings.SecureString;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.core.Strings;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.test.SecurityIntegTestCase;