posterior 1.6.0

Enhancements

• Add exclude option to subset_draws(), which can be used to exclude
  the matched selection.
• Add are_log_weights option to pareto_smooth(), which is necessary
  for correct Pareto smoothing computation if the input vector
  consists of log weights.
• Add pareto_smooth option to weight_draws(), to Pareto smooth
  weights before adding to a draws object.
• Add individual Pareto diagnostic functions (pareto_khat(),
  pareto_khat_threshold(), pareto_min_ss(), pareto_convergence_rate())
• thin_draws() now automatically thins draws based on ESS by default,
  and non-integer thinning is possible.
• Matrix multiplication of rvars can now be done with the base matrix
  multiplication operator (%*%) instead of %**% in R >= 4.3.
• variables(), variables<-(), set_variables(), and nvariables() now
  support a with_indices argument, which determines whether variable names
  are retrieved/set with ("x[1]", "x[2]" ...) or without ("x") indices
  (#208).
• Add extract_variable_array() function to extract variables with indices
  into arrays of iterations x chains x any remaining dimensions (#340).
• For types that support factor variables (draws_df, draws_list, and
  draws_rvars), extract_variable() and extract_variable_matrix() can
  now return factors.