Add additional GC related benchmark

Given this performance regression in Python 3.14, it would be nice if we had a benchmark which would have more clearly shown it before final release. I have a new GC specific benchmark but it doesn't do things that would show this regression.

We should consider adding a new benchmark. The key features would be:

• creating a bunch of net new container objects, in order to trigger many, potentially young generation, collections
• creating tuple objects that can be untracked by the GC, in order to avoid slowing down full collections

Ideally we prefer to avoid a micro or synthetic benchmark and instead find some kind of real application that shows this regression. E.g. near the 3.13 release, we found a GC regression shown by Sphinx building Python docs. Something like that would be good.

まず、リンクされている Python 3.14 のパフォーマンスリグレッションと、pull request 381 にある既存の GC 固有ベンチマークを読みます。合成マイクロベンチマークではなく、多数の新しいコンテナオブジェクトと追跡不能なタプルを生成してリグレッションを明らかにする実際のアプリケーションのベンチマークを調査します。完了とは、リリース前にベンチマークがこの挙動を明確に示すことです。