Investigate why build scripts are slower than presets

I haven't done a deep enough dive on what the scripts are doing internally so I can't comment on the difference, but I've noticed empirically that it is much slower than just directly using the preset.

The feedback loop was really slow for me personally. If I made a small syntactical error in writing my code, it would take 2-3 minutes from running the build scripts before I got to see the error. That compounds really hard, where as running the preset build directly the feedback is nearly instantaneous.

_Originally posted by @ZelboK in https://github.com/NVIDIA/cccl/pull/647#discussion_r1380236424_

Start by comparing the build scripts with the directly used preset, focusing on the steps that make syntax-error feedback take 2–3 minutes instead of being nearly instantaneous. Trace the scripts' internal work and document the cause and a measurable improvement in the feedback loop.

Written by the indexing model from the issue text.