[18.0][FIX] sale_stock_picking_invoicing: stabilize matrix tests

[grojof]

Summary

• Stabilize sale_stock_picking_invoicing tests for strict matrix variants.
• Keep existing test goals while isolating environment-dependent side effects.

Why

In strict OCB runs, company creation in one test could trigger internal project creation and fail due additional required fields in mixed stacks. The test now isolates that side effect and remains focused on the default policy assertion.

Changes

• sale_stock_picking_invoicing/tests/test_sale_stock.py
  • In test_default_value_sale_invoicing_policy, isolate internal project side effects during company creation and keep assertion scope limited to sale_invoicing_policy default behavior.

Validation

• Local simulation (quick_nodemo) on integrated scenario (approved baseline + migration stack) is green:
  • odoo_exclude=0
  • ocb_exclude=0
  • Run artifacts: tmp-lab/tmp/runs/20260221-231040-pr2063_on_approved_after_fixes_v3

Merge order

4/4 (after #2271 and #2272)

Depends on:

• [18.0][FIX] account_invoice_auto_send_by_email: set trusted outgoing bank in tests #2271
• [18.0][FIX] tests: stabilize account_billing/custom_rounding/show_currency_rate #2272

[OCA-git-bot]

Hi @renatonlima, @mbcosta,
some modules you are maintaining are being modified, check this out!

[grojof]

Cross-reference: migration follow-up has been posted on #2063 for rerun with the updated 18.0 context (after #2271-#2274 stabilization).

Ref: #2063 (comment)

[grojof]

Update pushed to this PR branch:

• [18.0][FIX] sale_stock_picking_invoicing: isolate company default policy test

This was identified during a strict integrated local simulation (approved baseline + migration stack).
Current local result for that scenario is green (odoo_exclude=0, ocb_exclude=0).

[grojof]

Follow-up fix pushed for the failing CI run on this PR:

• [18.0][FIX] sale_stock_picking_invoicing: guard optional project patch in test

Root cause:

• test_default_value_sale_invoicing_policy patched _create_internal_project_task unconditionally.
• In some matrix variants that method is not present on res.company, so the test failed with:
  AttributeError: <class 'odoo.api.res.company'> does not have the attribute '_create_internal_project_task'.

Fix:

• Apply the patch only when the method exists (hasattr), otherwise create the company directly.
• Test intent remains unchanged (assert default sale_invoicing_policy).

[grojof]

Follow-up coverage-oriented refinement pushed:

• [18.0][FIX] sale_stock_picking_invoicing: simplify optional method patch

Details:

• Replaced the conditional branch with a single patch.object(..., create=True) flow.
• This keeps compatibility when _create_internal_project_task is absent and reduces uncovered diff lines.
• Also fixed a local issue (autospec cannot be used with create=True) by using a valid mock configuration.

Goal: improve Codecov patch coverage while preserving test behavior.