HHH-13874 - Deprecating methods that will be removed soon

Two methods that are dropped in v6.0 are now marked as deprecated in this commit.

As discussed in the removal PR https://github.com/hibernate/hibernate-orm/pull/3229

hibernate-core/src/main/java/org/hibernate/mapping/Constraint.java

@@ -156,6 +156,7 @@ public abstract class Constraint implements RelationalModel, Exportable, Seriali
 		return columns.iterator();
 	}
 
+	@Deprecated
 	public Iterator<Column> columnIterator() {
 		return columns.iterator();
 	}

hibernate-testing/src/main/java/org/hibernate/testing/junit4/BaseCoreFunctionalTestCase.java

@@ -236,6 +236,7 @@ public abstract class BaseCoreFunctionalTestCase extends BaseUnitTestCase {
 		return NO_MAPPINGS;
 	}
 
+	@Deprecated
 	protected String[] getXmlFiles() {
 		// todo : rename to getOrmXmlFiles()
 		return NO_MAPPINGS;