SQLiteCpp's option(BUILD_SHARED_LIBS OFF) sets the variable in cache,
which then leaks into libzip's build. libzip defaults to ON but sees
the cached OFF value, causing it to attempt linking against
zstd::libzstd_static which doesn't exist when only the shared library
is installed (e.g., on Arch Linux).
Fix by explicitly setting BUILD_SHARED_LIBS=ON before add_subdirectory(libzip).
Robin E.R. Davies