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).

website/scripts/extract-skills.py

@@ -309,7 +309,7 @@ MIN_CATEGORY_SIZE = 4
 
 def _consolidate_small_categories(skills: list) -> list:
     for s in skills:
-        if s["category"] in ("uncategorized", ""):
+        if s["category"] in {"uncategorized", ""}:
             s["category"] = "other"
             s["categoryLabel"] = "Other"
 

website/scripts/generate-llms-txt.py

@@ -280,7 +280,7 @@ def emit_llms_full() -> str:
         rel = path.relative_to(DOCS)
         parts = rel.parts
         if len(parts) >= 3 and parts[0] == "user-guide" and parts[1] == "skills" \
-                and parts[2] in ("bundled", "optional"):
+                and parts[2] in {"bundled", "optional"}:
             continue
         seen.add(path)
         meta, body = read_frontmatter(path)