GZipMiddleware

This release focuses on enhancing the `GZipMiddleware` with new configuration options and improved handling of streamed and partial responses.

This release introduces improvements to GZipMiddleware by lazily allocating resources and offloading large compression tasks. It also updates the internal implementation to use `zlib.compressobj` for potentially better performance.

Starlette 0.46.0 adds a Vary header to GZipMiddleware, renames MultiPartParser’s `max_file_size` to `spool_max_size`, and deprecates `TestClient(timeout=…)`, while fixing background task exception handling and SSE compression.