### 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
final SamlServiceProviderResolver serviceResolver = Mockito.mock(SamlServiceProviderResolver.class);
        final WildcardServiceProviderResolver wildcardResolver = Mockito.mock(WildcardServiceProviderResolver.class);
        final CloudServiceProvider serviceProvider = new CloudServiceProvider(
            "https://sp.some.org",
            "test sp",
            true,
            new URL("https://sp.some.org/api/security/v1/saml"),
            TRANSIENT,
            Duration.ofMinutes(5),
            null,
            new SamlServiceProvider.AttributeNames(
                "https://saml.elasticsearch.org/attributes/principal",
                "https://saml.elasticsearch.org/attributes/name",
                "https://saml.elasticsearch.org/attributes/email",
                "https://saml.elasticsearch.org/attributes/roles"
            ),
            null,
            false,
            false
        );
        mockRegisteredServiceProvider(serviceResolver, "https://sp.some.org", serviceProvider);
        mockRegisteredServiceProvider(serviceResolver, "https://sp2.other.org", null);
        final ServiceProviderDefaults defaults = new ServiceProviderDefaults("elastic-cloud", TRANSIENT, Duration.ofMinutes(15));
        final X509Credential signingCredential = readCredentials("RSA", randomFrom(1024, 2048, 4096));
        final SamlIdentityProvider idp = SamlIdentityProvider.builder(serviceResolver, wildcardResolver)
            .fromSettings(env)
            .signingCredential(signingCredential)
            .serviceProviderDefaults(defaults)
            .build();
        final SamlFactory factory = new SamlFactory();