Recache processes to make sure we close them all.

[germa89]

This come from internal request:

this is a follow-up on my last service request.
We had issues with closing processes when using the SMP mode within a PyAnsys script.
Your service member O.R. helped a lot and suggested to upgrade our python package with the following command.
pip install --upgrade --upgrade-strategy eager ansys-mapdl-core The issue unfortunately still exists.
DMP mode seem to work just fine with my crack growth (SMART) analysis.

I did try locally in ubuntu container, and on Windows 11; and it seems to work.

I will ask for internal feedback.

=Edit=
I have also added the module atexit to track exiting python using __del__ method properly.
Close #1812

[codecov]

Codecov Report

Merging #1831 (9c95b41) into main (4e93251) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1831   +/-   ##
=======================================
  Coverage   85.69%   85.69%           
=======================================
  Files          44       44           
  Lines        7809     7811    +2     
=======================================
+ Hits         6692     6694    +2     
  Misses       1117     1117