### 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
} else {
            certificateChain = List.of(clientCertificate, intermediateCA, rootCA);
        }
        final RequestOptions testUserOptions = RequestOptions.DEFAULT.toBuilder()
            .addHeader(
                "Authorization",
                basicAuthHeaderValue(
                    SecuritySettingsSource.TEST_USER_NAME,
                    new SecureString(SecuritySettingsSourceField.TEST_PASSWORD.toCharArray())
                )
            )
            .build();
        final TestSecurityClient securityClient = getSecurityClient(testUserOptions);
        
        String roleMapping = """
            {
                "enabled": true,
                "roles": [ "role_by_delegated_user" ],
                "rules": {
                  "field": { "metadata.pki_delegated_by_user": "test_user" }
                }
            }
            """;
        securityClient.putRoleMapping("role_by_delegated_user", roleMapping);
        roleMapping = """
            {
                "enabled": true,
                "roles": [ "role_by_delegated_realm" ],
                "rules": {
                  "field": { "metadata.pki_delegated_by_realm": "file" }