Add checks to `determine_n_jobs` and add test for it

[kasyanovse]

Fix for https://github.com/aimclub/FEDOT/issues/1170.

[codecov-commenter]

Codecov Report

Merging #202 (1998582) into main (3234a52) will increase coverage by 0.21%. Report is 4 commits behind head on main. The diff coverage is 78.18%.

@@            Coverage Diff             @@
##             main     #202      +/-   ##
==========================================
+ Coverage   74.13%   74.35%   +0.21%     
==========================================
  Files         129      130       +1     
  Lines        7687     7760      +73     
==========================================
+ Hits         5699     5770      +71     
- Misses       1988     1990       +2     

Files Changed	Coverage Δ
golem/core/dag/graph.py	77.01% <ø> (ø)
golem/visualisation/opt_history/fitness_line.py	35.15% <0.00%> (ø)
golem/core/optimisers/adaptive/reward_agent.py	47.61% <47.61%> (ø)
...misers/adaptive/mab_agents/contextual_mab_agent.py	35.71% <50.00%> (+4.04%)	:arrow_up:
...olem/core/optimisers/genetic/operators/mutation.py	89.21% <50.00%> (ø)
...m/core/optimisers/adaptive/mab_agents/mab_agent.py	75.00% <81.57%> (+34.45%)	:arrow_up:
...ore/optimisers/genetic/operators/base_mutations.py	90.81% <85.71%> (-0.56%)	:arrow_down:
...adaptive/mab_agents/neural_contextual_mab_agent.py	77.77% <100.00%> (ø)
golem/core/optimisers/adaptive/operator_agent.py	92.17% <100.00%> (+0.99%)	:arrow_up:
golem/core/optimisers/genetic/evaluation.py	94.40% <100.00%> (+0.17%)	:arrow_up:
... and 3 more

... and 1 file with indirect coverage changes