fix display and confint of bootstrap for models without dispersion parameter

[palday]

closes #859

• add entry in NEWS.md
• after opening this PR, add a reference and run docs/NEWS-update.jl to update the cross-references.
• I've bumped the version appropriately

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.46%. Comparing base (50f0ac9) to head (9744074).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #861   +/-   ##
=======================================
  Coverage   95.45%   95.46%           
=======================================
  Files          38       38           
  Lines        3676     3681    +5     
=======================================
+ Hits         3509     3514    +5     
  Misses        167      167           

Flag	Coverage Δ
current	95.16% <100.00%> (+<0.01%)	⬆️
minimum	95.46% <100.00%> (+<0.01%)	⬆️

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[dmbates]

This looks fine to me but I would appreciate if @ararslan also had a look.

[palday]

@ararslan I need this for demo'ig something today, but posthoc review is appreciated!

[ararslan]

It might be safer, albeit slower, to check any(ismissing, tbl.σ) in case inference decides that the element type of tbl.σ is Any. You could do something like

Tσ = eltype(tbl.σ)
if k == "σ" && ((Tσ !== Any && Missing <: Tσ) || (Tσ === Any && any(ismissing, tbl.σ)))
    return false
end