OZG-6754 Use default value for XInclude processing

XInclude processing defaults to false.
https://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html#setXIncludeAware-boolean-

src/main/java/de/ozgcloud/xta/client/xdomea/XdomeaXtaMessageCreatorFactory.java

@@ -134,7 +134,6 @@ public class XdomeaXtaMessageCreatorFactory {
 		try {
 			documentBuilderFactory.setFeature(DISALLOW_DOCTYPE_DECL_FEATURE_URL, true);
 			documentBuilderFactory.setNamespaceAware(true);
-			documentBuilderFactory.setXIncludeAware(false);
 			documentBuilderFactory.setSchema(createSchema());
 			log.debug("Creating new document builder...");
 			var documentBuilder = documentBuilderFactory.newDocumentBuilder();

src/test/java/de/ozgcloud/xta/client/xdomea/XdomeaXtaMessageCreatorFactoryTest.java

@@ -124,17 +124,6 @@ class XdomeaXtaMessageCreatorFactoryTest {
 			verify(documentBuilderFactory).setFeature(DISALLOW_DOCTYPE_DECL_FEATURE_URL, true);
 		}
 
-		@DisplayName("should not process XInclude markup")
-		@Test
-		@SneakyThrows
-		void shouldNotProcessXIncludeMarkup() {
-			setupMocks();
-
-			factory.create();
-
-			verify(documentBuilderFactory).setXIncludeAware(false);
-		}
-
 		@DisplayName("should set document builder namespace aware")
 		@Test
 		@SneakyThrows