Enable multithreading and libdeflate compressor support

Enable multithreading

erofs-utils 1.8 added support for multi-threaded compression.

Note that according to https://git.kernel.org/xiang/erofs-utils/c/830b27bc233421b91ea66b55a3fcc69a99870af8

Multi-threaded compression is not compatible with -Ededupe,
-E(all-)fragments for now.

Enable libdeflate compressor support

This allows to use DEFLATE compression via libdeflate. E.g.: mkfs.erofs -zlibdeflate.