[12.x] Avoid unnecessary filtering when no callback is provided

[AhmedAlaa4611]

Description

This PR refactors the recorded() method in the HTTP client to avoid an unnecessary call to filter() when no callback is provided.

Currently, when $callback is null, the method creates a default closure that always returns true, then filters the entire collection; effectively doing nothing but still iterating over the data.

This change short-circuits that path by simply returning the collection directly when no filtering is needed, resulting in slightly better performance and improved clarity, especially when dealing with large numbers of recorded request/response pairs.