[FIX] fleet: Fix compute method to work in batch

closes odoo/odoo#64716

X-original-commit: a408494c6be551e169a8eec2d76cd57acda97fee
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/fleet/models/fleet_vehicle.py

@@ -33,10 +33,11 @@ class FleetVehicle(models.Model):
 
     @api.depends('model_id')
     def _compute_manager_id(self):
-        if self.model_id:
-            self.manager_id = self.model_id.manager_id
-        else:
-            self.manager_id = None
+        for vehicle in self:
+            if vehicle.model_id:
+                vehicle.manager_id = vehicle.model_id.manager_id
+            else:
+                vehicle.manager_id = None
 
     brand_id = fields.Many2one('fleet.vehicle.model.brand', 'Brand', related="model_id.brand_id", store=True, readonly=False)
     log_drivers = fields.One2many('fleet.vehicle.assignation.log', 'vehicle_id', string='Assignment Logs')