[REF] l10n_fr_account: host custom migration scripts in a dedicated `--upgrade-path`

Custom migration scripts for a core module used to require copying the
whole module into ``versions/18.0/addons/`` so its ``migrations/`` folder
would be picked up. Because the migration container mounts that copy with
priority (``--addons-path=mig,addons``) and ``get_module_path`` returns the
first match, the copy fully shadowed the core module — dragging along its
entire data/models just to carry one script.

Instead, inject the scripts through a dedicated OpenUpgrade ``upgrade_path``:

- New ``versions/18.0/scripts/l10n_fr_account/18.0.2.2/`` holding
  ``pre-migration-0k-fix-orphan-expressions.py`` (converted to the
  ``@openupgrade.migrate()`` / ``migrate(env, version)`` convention) and
  ``post-migration-0k-vat-box25.py`` + ``noupdate_changes.xml`` that reapply
  the box 25 VAT-report customization via ``openupgrade.load_data``.
- ``config/compose.yml``: mount it as ``/opt/odoo/auto/upgrade`` for ou18.
- ``versions/18.0/upgrade.sh``: pass
  ``--upgrade-path=/opt/odoo/auto/upgrade,/opt/odoo/auto/addons/openupgrade_scripts/scripts``.
  Odoo appends every path to ``odoo.upgrade.__path__`` and concatenates the
  per-version scripts, so our scripts run IN ADDITION to the native ones;
  the native path is listed explicitly because ``--upgrade-path`` overrides
  ``config['upgrade_path']`` which ``openupgrade_framework`` only sets when empty.

Files are named with a ``-0k-`` marker so they never collide with the native
``pre-migration.py`` / ``post-migration.py``. This removes the need for the
shadowing module copy entirely.

Also ignore ``__pycache__``/``*.pyc``.

versions/18.0/scripts/l10n_fr_account/18.0.2.2/post-migration-0k-vat-box25.py

@@ -0,0 +1,20 @@
+# Copyright 0k / Élabore
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+#
+# Custom OpenUpgrade migration script, injected through a dedicated
+# --upgrade-path (see versions/18.0/upgrade.sh). It runs IN ADDITION to the
+# native openupgrade_scripts post-migration.py of l10n_fr_account/18.0.2.2.
+#
+# Loads the 0k customization of the French VAT report (box 25 "adjustment")
+# the OpenUpgrade way, without shadowing the core l10n_fr_account module.
+from openupgradelib import openupgrade
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    # mode="init" (re)creates records marked noupdate that the normal upgrade
+    # mechanism would skip; it updates existing ones (tax_report_25_formula)
+    # and creates new ones (tax_report_25_adjustment).
+    openupgrade.load_data(
+        env, "l10n_fr_account", "18.0.2.2/noupdate_changes.xml"
+    )