unpivot

This release introduces several performance improvements, new features like Iceberg schema evolution and correlated subqueries, and numerous bug fixes. It also deprecates the `rechunk` parameter and related functions.

This release focuses heavily on performance improvements across streaming, I/O, and core computations, alongside numerous bug fixes for stability and correctness. A key change is the deprecation of the `retries` argument in favor of using `storage_options`.

This release introduces significant enhancements across SQL support (including window functions and QUALIFY), new DataFrame/Expr methods like bin slicing and improved rolling calculations, and numerous performance optimizations, especially for streaming and Parquet I/O. Numerous bugs related to panics, dtype handling, and SQL expression resolution have also been fixed.

This release focuses heavily on performance improvements by lowering operations like `.sort(maintain_order=True).head()` and `rle` to the streaming engine. Numerous bug fixes address issues across data types, serialization, and expression evaluation.