[REF] all: pass pre-commit on the whole repo

Needed for the lint job of the CI to go green. Mostly automatic hook
fixes (black, isort, prettier, pyupgrade, autoflake, whitespace). By hand:

- flake8: two unused imports, an ambiguous variable name `l`.
- pylint-odoo mandatory: manifest keys equal to their default value
  (installable, application, data, external_dependencies).
- end-of-file-fixer skips *.patch too, like trailing-whitespace: the
  upstream patches stay as git format-patch wrote them.

No behaviour change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

purchase_rappel/tests/test_purchase_rappel.py

@@ -4,6 +4,7 @@
 from odoo import fields
 from odoo.exceptions import UserError
 from odoo.tests import tagged
+
 from odoo.addons.account.tests.common import AccountTestInvoicingCommon