[IMP] project: Remove personal stage garbage collector

Will be reintroduced properly afterward. Currently, even if the
field is defined using ondelete='set null', the M2M relation
doesn't handle the fact that the target table is a real model
and not a simple relational table.

closes odoo/odoo#116880

X-original-commit: f58d2ad669710a353263e418bbf69f5f49145cac
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/project/models/project_task_type.py

@@ -145,7 +145,3 @@ class ProjectTaskType(models.Model):
             'stage_id': new_stage.id,
         })
         self.unlink()
-
-    @api.autovacuum
-    def _gc_personal_stages(self):
-        self.env['project.task.type'].search([('user_id.active', '=', False)], limit=1000).unlink()