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/discourse/test_restore.py

@@ -13,13 +13,11 @@ from harness import lifecycle  # noqa: E402
 
 
 def _psql(domain, sql):
-    cmd = (
-        "PGPASSWORD=$(cat /run/secrets/db_password) " f'psql -U discourse -d discourse -tAc "{sql}"'
-    )
+    cmd = f'PGPASSWORD=$(cat /run/secrets/db_password) psql -U discourse -d discourse -tAc "{sql}"'
     return lifecycle.exec_in_app(domain, ["sh", "-c", cmd], service="db").strip()
 
 
 def test_restore_returns_state(live_app):
-    assert (
-        _psql(live_app, "SELECT v FROM ci_marker;") == "original"
-    ), "restore did not return the pre-mutation discourse postgres state (data-integrity failure)"
+    assert _psql(live_app, "SELECT v FROM ci_marker;") == "original", (
+        "restore did not return the pre-mutation discourse postgres state (data-integrity failure)"
+    )