[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>

.pre-commit-config.yaml

@@ -68,8 +68,9 @@ repos:
             # lines of a diff are a single space, stripping it breaks them
             exclude: /README\.rst$|\.pot?$|\.patch$
           - id: end-of-file-fixer
-            # exclude autogenerated files
-            exclude: /README\.rst$|\.pot?$
+            # exclude autogenerated files, and patches: they are kept as
+            # git format-patch wrote them
+            exclude: /README\.rst$|\.pot?$|\.patch$
           - id: debug-statements
           - id: check-case-conflict
           - id: check-docstring-first