[17.0] mrp_mass_production_order: test fails

[MeritxellAForgeFlow]

Module

mrp_mass_production_order

Describe the bug

The test test_mrp_mass_production_order fails:
line 50, in setUpClass
cls.mrp1, cls.mrp2 = cls.env["mrp.production"].search(
^^^^^^^^^^^^^^^^^^
ValueError: too many values to unpack (expected 2)

To Reproduce

Affected versions: 17.0

Steps to reproduce the behavior:

1. Install account_move_line_stock_info,date_range,hr_timesheet,mrp,mrp_subcontracting,product,purchase,purchase_stock,repair,sale_stock,stock,stock_demand_estimate,stock_warehouse_calendar,web_widget_x2many_2d_matrix
2. Install mrp_mass_production_order
3. Run the module

Additional context
This bug is the cause of the error in this PR https://github.com/OCA/manufacture/actions/runs/12650345076/job/35248675151?pr=1441

@DavidJForgeFlow @peluko00