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/gitea/test_install.py

@@ -65,8 +65,8 @@ def test_install_gitea(live_app, meta):
             )
             page.wait_for_selector("input#user_name", timeout=20_000)
             content = page.content()
-            assert (
-                "gitea" in content.lower() or "sign in" in content.lower()
-            ), "Sign-in page did not render expected gitea content"
+            assert "gitea" in content.lower() or "sign in" in content.lower(), (
+                "Sign-in page did not render expected gitea content"
+            )
         finally:
             browser.close()