Currently a ParseError is arising when the user installs the `pos_settle_due` module after deleting the `Services` in Product Categories/Configuration.

Steps to reproduce:
---
- Install `Invoicing` application (without demo data).
- Invoicing > Configuration > Product Categories > Delete `Services`
- Now install `pos_settle_due` module

Traceback:
---
```
ValueError: External ID not found in the system: product.product_category_services

ParseError: while parsing /home/odoo/src/enterprise/saas-18.3/pos_settle_due/data/pos_settle_due_data.xml:22, somewhere inside <record id="product_product_settle_invoice" model="product.product">
            <field name="name">Settle Invoice</field>
            <field name="categ_id" ref="product.product_category_services"/>
            <field name="type">service</field>
            <field name="weight">0.00</field>
            <field name="available_in_pos">False</field>
            <field name="taxes_id" eval="[]"/>
        </record>
```

The error occurs because the user deleted `Services` in Product Categories, and then tried to install the other module.

This commit resolves the error by providing a False value for the field if the product category is missing.

sentry-6377659355