Update SamlRealmTests to use TLSv1.2 only (#75324)

Recent JDK builds disable TLSv1 and TLSv1.1, which would cause this test
to fail whenever it was (randomly) configured to use those protocols.

For the purposes of this test it is no longer necessary to test with
older protocols, and the test can rely on TLSv1.2 instead.

Resolves: #73314

x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/saml/SamlRealmTests.java

@@ -85,7 +85,6 @@
 /**
  * Basic unit tests for the SAMLRealm
  */
-@SamlTestCase.AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/73314")
 public class SamlRealmTests extends SamlTestCase {
 
     public static final String TEST_IDP_ENTITY_ID = "http://demo_josso_1.josso.dev.docker:8081/IDBUS/JOSSO-TUTORIAL/IDP1/SAML2/MD";
@@ -120,7 +119,7 @@ public void testReadIdpMetadataFromFile() throws Exception {
     }
 
     public void testReadIdpMetadataFromHttps() throws Exception {
-        final String serverProtocol = randomFrom("TLSv1", "TLSv1.1", "TLSv1.2");
+        final String serverProtocol = "TLSv1.2";
         final Path path = getDataPath("idp1.xml");
         final String body = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
         final MockSecureSettings mockSecureSettings = new MockSecureSettings();