### 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
import org.elasticsearch.test.SecuritySettingsSource;
import org.elasticsearch.test.SecuritySettingsSourceField;
import org.elasticsearch.test.TestSecurityClient;
import org.elasticsearch.test.rest.ESRestTestCase;
import org.elasticsearch.xcontent.ObjectPath;
import org.elasticsearch.xcontent.ParseField;
import org.elasticsearch.xpack.core.XPackSettings;
import org.elasticsearch.xpack.core.security.action.realm.ClearRealmCacheRequestBuilder;
import org.elasticsearch.xpack.core.security.authc.support.Hasher;
import org.elasticsearch.xpack.core.security.user.User.Fields;
import org.junit.Before;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import static org.elasticsearch.test.TestMatchers.throwableWithMessage;
import static org.elasticsearch.xpack.core.security.authc.support.UsernamePasswordToken.basicAuthHeaderValue;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.empty;
import static org.hamcrest.Matchers.hasEntry;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
@LuceneTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/97756")