Check LD_LIBRARY_PATH on setup

[gembancud]

Issue: Instructions when compiling to source require setting the destination of binaries in env var LD_LIBRARY_PATH. This env is not checked during library setup, so unshipped self-compiled binaries will remain undetected. Soln: Adds a check to LD_LIBRARY PATH.

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

[TimDettmers]

I have to check this more carefully when I have more time. Thank you for your contribution! Sorry for taking so long to look at this.

[akx]

Related: https://github.com/TimDettmers/bitsandbytes/pull/1041#issuecomment-1931634146