Revert "initial upsampfact tweak (#638)"

This reverts commit 30de078.

Author: DiamonDinoia

CHANGELOG

@@ -3,8 +3,6 @@ If not stated, FINUFFT is assumed (cuFINUFFT <=1.3 is listed separately).
 
 Master, using release name V 2.4.0 (2/11/25)
 
-* Tweaked choice of upsampfact to use a density based heuristic for type 1 and 2
-  in the CPU library. This gives a significant speedup for some cases.
 * Removed FINUFFT_CUDA_ARCHITECTURES flag, as it was unnecessary duplication.
 * Enabled LTO for finufft, nvcc support is flaky at the moment.
 * Added GPU spread interp only test. Added CPU spread interp only test to cmake