fix: git blame line check

[ianlewis]

Description:

Fix the line check for git blame results.

Related Issues:

N/A

Checklist:

• Review the CONTRIBUTING.md documentation.
• Add a reference to a related issue in the repository.
• Add a description of the changes proposed in the pull request.
• Add unit tests if applicable.
• Update documentation if applicable.
• Add a note in the CHANGELOG.md if applicable.
• Sign the Google CLA.

[ianlewis]

Should add a unit test for this.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 77.86%. Comparing base (163014e) to head (215bf3e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1517   +/-   ##
=======================================
  Coverage   77.86%   77.86%           
=======================================
  Files          17       17           
  Lines        1057     1057           
=======================================
  Hits          823      823           
  Misses        171      171           
  Partials       63       63           

Files	Coverage Δ
internal/walker/walker.go	59.32% <0.00%> (ø)