### Description

In [TransportSamlInitiateSingleSignOnActionTests.java](https://github.com/elastic/elasticsearch/pull/98882/files#diff-26733d11b06442213a040cc3d5c89595300ec813bb31076874afa38ef2ad3b91),  `/api/security/v1/saml` (deprecated) should be replaced with /api/security/saml/callback

In https://github.com/elastic/kibana/blob/b33effa182bcb7c9620c5435ab252d8067732655/x-pack/plugins/security/server/routes/authentication/saml.ts#L27

/api/security/saml/callback is the correct URL,
while /api/security/v1/saml is the deprecated URL.

Related to https://github.com/elastic/cloud-on-k8s/issues/7118
x-pack/plugin/identity-provider/src/test/java/org/elasticsearch/xpack/idp/action/TransportSamlInitiateSingleSignOnActionTests.java
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.core.Strings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.env.TestEnvironment;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.Transport;
import org.elasticsearch.transport.TransportService;
import org.elasticsearch.xpack.core.security.SecurityContext;
import org.elasticsearch.xpack.core.security.authc.Authentication;
import org.elasticsearch.xpack.core.security.authc.AuthenticationTestHelper;
import org.elasticsearch.xpack.core.security.authc.support.SecondaryAuthentication;
import org.elasticsearch.xpack.core.security.user.User;
import org.elasticsearch.xpack.idp.privileges.ServiceProviderPrivileges;
import org.elasticsearch.xpack.idp.privileges.UserPrivilegeResolver;
import org.elasticsearch.xpack.idp.saml.idp.SamlIdentityProvider;
import org.elasticsearch.xpack.idp.saml.sp.CloudServiceProvider;
import org.elasticsearch.xpack.idp.saml.sp.SamlServiceProvider;
import org.elasticsearch.xpack.idp.saml.sp.SamlServiceProviderResolver;
import org.elasticsearch.xpack.idp.saml.sp.ServiceProviderDefaults;
import org.elasticsearch.xpack.idp.saml.sp.WildcardServiceProviderResolver;
import org.elasticsearch.xpack.idp.saml.support.SamlAuthenticationState;
import org.elasticsearch.xpack.idp.saml.support.SamlFactory;
import org.elasticsearch.xpack.idp.saml.test.IdpSamlTestCase;
import org.mockito.Mockito;
import org.opensaml.saml.saml2.core.StatusCode;
import org.opensaml.security.x509.X509Credential;
import java.net.URL;
import java.time.Duration;