### 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
X509Certificate bogusCertificate = readCertForPkiDelegation("bogus.crt");
        RequestOptions.Builder optionsBuilder = RequestOptions.DEFAULT.toBuilder();
        optionsBuilder.addHeader(
            "Authorization",
            basicAuthHeaderValue(
                SecuritySettingsSource.TEST_USER_NAME,
                new SecureString(SecuritySettingsSourceField.TEST_PASSWORD.toCharArray())
            )
        );
        
        final List<X509Certificate> certificateChain1 = List.of(clientCertificate);
        ResponseException e1 = expectThrows(
            ResponseException.class,
            () -> getSecurityClient(optionsBuilder.build()).delegatePkiAuthentication(certificateChain1)
        );
        assertThat(
            e1,
            throwableWithMessage(
                containsString(
                    "unable to authenticate user [O=org, OU=Elasticsearch, CN=Elasticsearch Test Client]"
                        + " for action [cluster:admin/xpack/security/delegate_pki]"
                )
            )
        );
        
        final List<X509Certificate> certificateChain2 = Arrays.asList(intermediateCA, clientCertificate);
        ResponseException e2 = expectThrows(
            ResponseException.class,
            () -> getSecurityClient(optionsBuilder.build()).delegatePkiAuthentication(certificateChain2)
        );