Use the proper PU for executeUpdate on entityClass

Fixes quarkusio#42314
Introduced by quarkusio#41547

(cherry picked from commit cf5f6bb)

extensions/panache/hibernate-orm-panache-common/runtime/src/main/java/io/quarkus/hibernate/orm/panache/common/runtime/AbstractJpaOperations.java

@@ -482,7 +482,7 @@ public int executeUpdate(Class<?> entityClass, String panacheQuery, Object... pa
 
         try {
             String updateQuery = PanacheJpaUtil.createUpdateQuery(entityClass, panacheQuery, paramCount(params));
-            return bindParameters(getSession(DEFAULT_PERSISTENCE_UNIT_NAME).createMutationQuery(updateQuery), params)
+            return bindParameters(getSession(entityClass).createMutationQuery(updateQuery), params)
                     .executeUpdate();
         } catch (RuntimeException x) {
             throw NamedQueryUtil.checkForNamedQueryMistake(x, panacheQuery);