Improvement: just set rpath on repair everytime

[fzakaria]

Please let me know if you all appreciate these code improvements as I scan the code.

I am reading the code for repair.py and I believe it would be simpler to always just squash the RUNPATH/RPATH [1]

I see a few other improvements that can be made. Happy to upstream some if you find them useful.

[1] https://github.com/pypa/auditwheel/blob/3636dad88d6168aa745684db9ea6a7c6df4d4484/src/auditwheel/repair.py#L165