volume_type_projects deleted column is bogus

The cinder db table volume_type_projects has a 'deleted' column that is declared as an Integer here:
https://github.com/openstack/cinder/blob/master/cinder/db/sqlalchemy/models.py#L446

When the CinderBase model already has a deleted column which is declared as a Boolean here:
https://github.com/openstack/cinder/blob/master/cinder/db/sqlalchemy/models.py#L47

The problem with this is in the DB the deleted column values for the volume_type_projects ends up being the same value as the id column, which increments.

For example:
mysql> select id, deleted_at, deleted from volume_type_projects;
+----+---------------------+---------+
| id | deleted_at | deleted |
+----+---------------------+---------+
| 1 | 2020-08-14 15:52:09 | 1 |
| 2 | 2020-08-14 15:52:09 | 2 |
| 3 | 2020-08-14 15:52:09 | 3 |
+----+---------------------+---------+
3 rows in set (0.00 sec)

Since it's not declared as a Boolean, then it gets the ID value when it's soft deleted. IF we have code that checks for deleted == 1, then this doesn't work.

The column should be declared as Boolean.