Removing njoy21 library creation.

[jlconlin]

This is an attempt to remove the extra step of creating an NJOY21 library, which doesn't really make sense.

[nathangibson14]

I'm sure the reason NJOY21 had a library and an executable previously was because of the tests. This looks like it should work to me, but let me make sure of that before I approve.

There are some tweaks/clean up that could be done to the CMakeLists.txt file, but there's no need to do that when I'll be re-updating them soon enough anyway.

[jlconlin]

I'm sure the reason NJOY21 had a library and an executable previously was because of the tests. This looks like it should work to me, but let me make sure of that before I approve.

There are some tweaks/clean up that could be done to the CMakeLists.txt file, but there's no need to do that when I'll be re-updating them soon enough anyway.

This just reduces the cycle time for me so it was worth it to play around and see if I could speed things up.

[nathangibson14]

It works for me.