Changes:

• Added the -T parameter, which enables multi-threaded compression using an external thread
  pool implemented in lzbench. The input data is split into N blocks (with block size specified
  by the -b option) and each block is compressed independently using T threads. Since the blocks
  are processed independently, this may slightly reduce the compression ratio. This option also
  significantly increases memory usage, as each compressor instance is allocated T times.
• added bzip3 1.5.1
• updated zstd to 1.5.7 (thanks to @tansy)
• updated lzav 4.22 (thanks to @avaneev)
• fixed: lzma 24.09 was using 2 threads for level 5 and higher (a bug introduced in v2.0)
• removed max_block_size parameter and blosclz, shrinker, xpack codecs
• removed pithy (issues with incompressible data), Nakamichi Okamigan
• improvement: report compiler version (thanks to @danfe)
• improvement: reorganization of lzbench directories
• improvement: changed interface of compression and decompression functions (thanks to @tansy)