fix: misaligned error display in skctl xray

[drmorr0]

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Description

We double-counted columns in the error view when determining how much to truncate for the item name display in skctl xray, which led names getting truncated when they shouldn't have been.

Testing done

• manual testing
• it'd be sorta nice to have a snapshot test for this since the other snapshot tests didn't catch it, but it's kindof a pain to do so I didn't bother.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.81%. Comparing base (7b7fb4a) to head (5599980).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #165      +/-   ##
==========================================
- Coverage   72.84%   72.81%   -0.03%     
==========================================
  Files          55       55              
  Lines        2975     2972       -3     
==========================================
- Hits         2167     2164       -3     
  Misses        808      808              

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