Correct a few historical income tax bracket parameter values

[martinholmer]

A year or two ago, there were a few mistakes made in entering by hand the values of some II_brk? and PT_brk? amounts. This pull request fixes those incorrect tax parameter values. It also fixes the reforms/rounding2022.json reform used in the round-trip-reform test so that the round-trip-reform test does not fail. Also, the expected aggregate test results for 2020 and 2021 changed slightly given the correction in the tax bracket values.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.42%. Comparing base (ec0a4ef) to head (d9aab06).
Report is 1 commits behind head on master.

Additional details and impacted files

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  Coverage   99.42%   99.42%           
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  Files          13       13           
  Lines        2593     2593           
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  Hits         2578     2578           
  Misses         15       15           

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[jdebacker]

@martinholmer Thanks for this update. I was surprise to see how off some of those values were. From some spot checking, I found no errors in your updated values. Merging.