Given Pareto-k computes the minimum sample size for reliable Pareto
smoothed estimate (to have small probability of large error). See
section 3.2.3 in Vehtari et al. (2024). This function is exported
to be usable by other packages. For user-facing diagnostic functions, see
pareto_min_ss and pareto_diags.
ps_min_ss(k, ...)pareto k value
unused
minimum sample size
Other helper-functions:
ps_convergence_rate(),
ps_khat_threshold(),
ps_tail_length()