Clear company on the lot sequence in production scenario

Since 9191fe4b4da4, the sequence can not be restricted to a company.

Closes #13257
(grafted from 04fe7c297ff324c623d73fe852fd3403bdc74199)

--HG--
branch : 7.0

modules/production/tests/scenario_production_lot_number.rst

@@ -31,7 +31,7 @@ Create lot sequence::
 
     >>> sequence_type, = SequenceType.find(
     ...     [('name', '=', "Stock Lot")], limit=1)
-    >>> sequence = Sequence(name="Lot", sequence_type=sequence_type)
+    >>> sequence = Sequence(name="Lot", sequence_type=sequence_type, company=None)
     >>> sequence.save()
 
 Create product::