Diff constantly adding addDefaultValue for a timestamp column

[rndmrsh]

Hi,

Running Liquibase:diff for a timestamp column with a default value, Liquibase keeps adding addDefaultValue even if the default value is already set in the table.

Versions:
liquibase-core: 4.21.1
liquibase-hibernate5: 4.21.1
spring boot: 2.7.5
org.postgresql:postgresql: 42.3.7
java: 11

liquibase.properties:

referenceDriver=liquibase.ext.hibernate.database.connection.HibernateDriver
referenceUrl=hibernate:spring:com.example\
  ?dialect=org.hibernate.dialect.PostgreSQLDialect\
  &hibernate.physical_naming_strategy=org.hibernate.boot.model.naming.CamelCaseToUnderscoresNamingStrategy\
  &hibernate.implicit_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy

Example entity:

@Entity
@Table(name = "test_table")
public class TestEntity {
	@Id
	private Long id;
	@Column(columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
	private LocalDateTime timestamp;
}

Initial changelog to create this table:

<changeSet author="rndmrsh (generated)" id="1682492668200-1">
    <createTable tableName="test_table">
        <column name="id" type="BIGINT">
            <constraints nullable="false" primaryKey="true" primaryKeyName="test_tablePK"/>
        </column>
        <column defaultValueComputed="CURRENT_TIMESTAMP" name="timestamp" type="TIMESTAMP WITHOUT TIME ZONE"/>
    </createTable>
</changeSet>

Subsequent changelogs:

<changeSet author="rndmrsh (generated)" id="1682492714416-1">
    <addDefaultValue columnDataType="timestamp" columnName="timestamp" defaultValueComputed="CURRENT_TIMESTAMP" tableName="test_table"/>
</changeSet>