Fix Hibernate 7.4 dropping primary key on order_type_class_map join table

Hibernate 7.4 emits a unique constraint instead of a composite primary
key when a @jointable's explicit @UniqueConstraint covers exactly the
columns that would form the join table's primary key. OrderType was the
only @manytomany Set declaring such a redundant @UniqueConstraint, so its
order_type_class_map join table lost its primary key under hbm2ddl. This
broke the integration tests, whose dbUnit REFRESH operation needs a
primary key to update existing rows (NoPrimaryKeyException).

Remove the redundant @UniqueConstraint: the two FK columns are the natural
key of a Set join table, so hbm2ddl generates the composite primary key
again, matching the production schema that already defines it via
Liquibase. The annotation only affected hbm2ddl-generated DDL, so
production is unaffected.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dkayiwa

api/src/main/java/org/openmrs/OrderType.java

@@ -23,7 +23,6 @@
 import jakarta.persistence.ManyToMany;
 import jakarta.persistence.ManyToOne;
 import jakarta.persistence.Table;
-import jakarta.persistence.UniqueConstraint;
 
 import org.apache.commons.lang3.StringUtils;
 import org.hibernate.envers.Audited;
@@ -62,8 +61,7 @@ public class OrderType extends BaseChangeableOpenmrsMetadata {
 
 	@Independent
 	@ManyToMany
-	@JoinTable(name = "order_type_class_map", joinColumns = @JoinColumn(name = "order_type_id"), inverseJoinColumns = @JoinColumn(name = "concept_class_id"), uniqueConstraints = @UniqueConstraint(columnNames = {
-	        "order_type_id", "concept_class_id" }))
+	@JoinTable(name = "order_type_class_map", joinColumns = @JoinColumn(name = "order_type_id"), inverseJoinColumns = @JoinColumn(name = "concept_class_id"))
 	private Set<ConceptClass> conceptClasses;
 
 	/**