Patch 9.2.0306 fixed malformed lz4 extraction commands by using "tar -I lz4"
on Linux and leaving non-Linux tar implementations to auto-detect lz4 input.
That still fails on systems where tar does not support either -I lz4 or
automatic lz4 decompression, such as Solaris /usr/bin/tar.
Keep the existing Linux path using GNU tar's "-I lz4" support. For non-Linux
systems, use lz4 explicitly to decompress the archive to stdout and feed the
resulting tar stream to the configured tar extraction command. This is the
same style tar.vim already used for lz4 archives before patch 9.2.0306.
Follow-up for vim/vim#19925closes: vim/vim#20555b0ce576fbc
Co-authored-by: Vladimír Marek <vlmarek13@gmail.com>