[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>

website_membership_signup_required/README.md

@@ -120,4 +120,4 @@ Para reforzar la seguridad se podría sustituir el query param estático por un
 token HMAC firmado (vinculado a la sesión y al producto objetivo), de modo
 que solo el flujo de `cart_update` pueda generar un redirect válido y el
 acceso directo a `/web/signup` fuera de ese flujo quede restringido. Ver
-`requirements.md` §7 R-01.
+`requirements.md` §7 R-01.