lint: ruff format + one auto-fix so the push self-test is green again

`scripts/lint.sh --fix` from the pinned lint devshell: 90 Python files
reformatted (ruff format, mechanical) and one C420 (dict comprehension →
dict.fromkeys) in tests/unit/test_f211_sso_skip.py. The push self-test had
been failing at the lint stage since build 1313 (2026-08-31) on exactly
these files; nothing else changed.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FqkQq3CDmFWcQ7u1LzoyRz

tests/unit/test_f211_sso_skip.py

@@ -66,7 +66,7 @@ def _load_conftest():
 class _FakeItem:
     def __init__(self, keywords):
         # pytest `item.keywords` supports `in`; a dict suffices.
-        self.keywords = {k: True for k in keywords}
+        self.keywords = dict.fromkeys(keywords, True)
         self.markers = []
 
     def add_marker(self, mark):