Remove discrepancy from winner distribution plots

[endolith]

The ideal winner is relative to the voters, not relative to the random number generator. It should remove any random bias before plotting.

[endolith]

Applies to

• distributions_by_dispersion.py
• distributions_by_method.py
• distributions_by_n_cands.py
• tomlinson_2023_figure_3.py
• tomlinson_2023_figure_3_updated.py