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/bluesky-pds/custom/test_session_auth.py

@@ -30,6 +30,6 @@ def test_get_session_requires_auth(live_app):
         f"body: {body!r}"
     )
     # The XRPC error envelope is JSON with an `error` field per the atproto spec.
-    assert isinstance(body, dict) and body.get(
-        "error"
-    ), f"expected XRPC JSON error envelope; got: {body!r}"
+    assert isinstance(body, dict) and body.get("error"), (
+        f"expected XRPC JSON error envelope; got: {body!r}"
+    )