appimage-runtime v21.6.0

AppImage runtime with extended compression support, built on Ubuntu-20.04 and based on AppImageKit (commit #859090b6bd635ef, 2021-06-02):

• appimage-runtime - supports lz4, lzo, gzip, zstd, lzma, xz
• appimage-runtime-zstd - smaller, supports only zstd

Runtime dependencies are linux-vdso.so.1, libpthread.so.0, libc.so.6, libdl.so.2, ld-linux-x86-64.so.2.