Improve decorator typing and fix core sketch bug.
This version (v0.4.4) is planned to be the final release for V1 (unless further bugs are discovered). Theine V2 is currently being refactored and rewritten, with a focus on free-threading support and improved concurrency performance. V2 will be based on the Go version of Theine. Following the release of V2, the next planned feature is weighted cache.