[FIX] account: display product name in correct language in an invoice

[fw-bot]

Issue before this commit:

When creating an invoice using the child contact of a parent contact that has a different language with respect to the father, the label of the invoice line was not always displayed in the child contact language but in the father's contact language.

Steps to reproduce the issue:

1. Activate at least 2 languages (X and Y)
2. Create a product and set the translation for that product in the activated languages
3. Create a Contact with the language X
4. Create a child contact (invoice adress type) for that contact with language Y
5. Create a new invoice setting the customer as the child contact
6. Add the product you created
7. See the label is displayed in the language of the parent contact

Cause of the issue:

The computation of the invoice line name relied on line.partner_id.lang. However, the partner_id of the move line is automatically set to the commercial partner that can be different (can be the father's contact) to the contact used on the invoice. As a result, the product description was translated using the wrong language.

Reason to introduce the fix:

To ensure that invoice line labels are correctly translated according to the language of the selected invoice contact, the computation now uses the language of move_id.partner_id instead of line.partner_id. This guarantees consistent and expected behavior in multilingual environments, especially when using different contacts under the same commercial partner.

opw-5955875

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Forward-Port-Of: #254833

[robodoo]

[fw-bot]

@eesteerina @svfu-odoo cherrypicking of pull request #254833 failed.

stdout:

Auto-merging addons/account/models/account_move_line.py
Auto-merging addons/account/tests/test_account_move_entry.py
CONFLICT (content): Merge conflict in addons/account/tests/test_account_move_entry.py

Either perform the forward-port manually (and push to this branch, proceeding as usual) or close this PR (maybe?).

you can use git-fw to re-do the forward-port for you locally.

⚠️ after resolving this conflict, you will need to merge it via @robodoo.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[eesteerina]

@robodoo r+