Consistent support for JPA 3.2 transaction timeout

Closes gh-35663

spring-orm/src/main/java/org/springframework/orm/jpa/DefaultJpaDialect.java

@@ -59,11 +59,16 @@ public class DefaultJpaDialect implements JpaDialect, Serializable {
 	public @Nullable Object beginTransaction(EntityManager entityManager, TransactionDefinition definition)
 			throws PersistenceException, SQLException, TransactionException {
 
+		if (definition.getTimeout() != TransactionDefinition.TIMEOUT_DEFAULT) {
+			entityManager.getTransaction().setTimeout(definition.getTimeout());
+		}
+
 		if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
 			throw new InvalidIsolationLevelException(getClass().getSimpleName() +
 					" does not support custom isolation levels due to limitations in standard JPA. " +
 					"Specific arrangements may be implemented in custom JpaDialect variants.");
 		}
+
 		entityManager.getTransaction().begin();
 		return null;
 	}

spring-orm/src/main/java/org/springframework/orm/jpa/vendor/EclipseLinkJpaDialect.java

@@ -99,6 +99,10 @@ public class EclipseLinkJpaDialect extends DefaultJpaDialect {
 	public @Nullable Object beginTransaction(EntityManager entityManager, TransactionDefinition definition)
 			throws PersistenceException, SQLException, TransactionException {
 
+		if (definition.getTimeout() != TransactionDefinition.TIMEOUT_DEFAULT) {
+			entityManager.getTransaction().setTimeout(definition.getTimeout());
+		}
+
 		int currentIsolationLevel = definition.getIsolationLevel();
 		if (currentIsolationLevel != TransactionDefinition.ISOLATION_DEFAULT) {
 			// Pass custom isolation level on to EclipseLink's DatabaseLogin configuration.