chore: ruff auto-fix PLR6201 — tuple → set in membership tests (#23937)

Replace  with  for all literal-tuple
membership tests. Set lookup is O(1) vs O(n) for tuple — consistent
micro-optimization across the codebase.

608 instances fixed via `ruff --fix --unsafe-fixes`, 0 remaining.
133 files, +626/-626 (net zero).

batch_runner.py

@@ -795,7 +795,7 @@ class BatchRunner:
                 conversations = entry.get("conversations", [])
                 for msg in conversations:
                     role = msg.get("role") or msg.get("from")
-                    if role in ("user", "human"):
+                    if role in {"user", "human"}:
                         prompt_text = (msg.get("content") or msg.get("value", "")).strip()
                         break