Add skim: ultra-fast, high-throughput compression algorithm

[VantorreWannes]

I would like to propose adding skim to the Squash benchmark suite.

skim is an open-source, ultra-fast compression algorithm designed specifically for high-throughput scenarios where execution speed is prioritized over compression ratio. It occupies a unique point on the Pareto frontier, sitting between density and raw memcpy.

Silesia Benchmark Reference (Ryzen 7 7800X3D)

• Compression Speed: ~3.39 GB/s
• Decompression Speed: ~5.96 GB/s
• Ratio: ~64.5%

Integration Details

• Repository: https://github.com/VantorreWannes/skim
• License: MIT
• API: Written in Zig, but exposes a clean C API (simple state initialization, compression, and decompression functions), making it straightforward to wrap for Squash's C-based plugin architecture.

Adding skim would provide Squash users with a valuable addition in the extremely low-latency/high-speed compression space.