fix(pika): use ObjectProxy for ReadyMessagesDequeProxy to restore iterability with wrapt 2.x (#4461)

* use ObjectProxy for pika ReadyMessagesDequeProxy to restore iterability

wrapt 2.x BaseObjectProxy does not proxy __iter__, breaking iteration
over the wrapped deque. Switch to ObjectProxy which proxies all dunder
methods including __iter__.

Assisted-by: Claude Opus 4.6

* update changelog with PR number

Assisted-by: Claude Opus 4.6

* fix lint: import ordering and formatting

Assisted-by: Claude Opus 4.6