[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/models/res_config_settings.py

@@ -1,6 +1,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import fields, models
+from odoo import fields
+from odoo import models
 
 
 class ResConfigSettings(models.TransientModel):
@@ -9,4 +10,4 @@ class ResConfigSettings(models.TransientModel):
     membership_signup_required = fields.Boolean(
         related="website_id.membership_signup_required",
         readonly=False,
-    )
+    )