Cmake truncates the full link path to a shared library if it is missing
an SONAME in some undocumented scenarios. This causes builds in some
systems to fail if "lpeg" isn't a library on the system path.
The path of imported libraries aren't modified by cmake, so we can use
that as a workaround until a proper solution for this has been
identified.
Closes https://github.com/neovim/neovim/issues/23395.