fix(changelog): ignore empty lines when using split_commits

[AntoineGS]

Description

Prevent duplication of changelog when using split_commit and the commits have empty lines.

Motivation and Context

When using split commits, if there is a an empty line between commits, it will duplicate the commit prior to the empty line, and I noticed that it will sometimes assign it to a different scope, though I have not investigated the why at this point.
One of the reasons this is a problem is that in certain GUIs (like GitHub Desktop) if you enter the first line in the header and the second line in the body, it will automatically add a new line.
fixes #606

How Has This Been Tested?

Using the existing test (changelog_generator_split_commits) by adding a new line in one of the commits.

Screenshots / Logs (if applicable)

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (no code change)
• Refactor (refactoring production code)
• Other

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I have formatted the code with rustfmt.
• I checked the lints with clippy.
• I have added tests to cover my changes.
• All new and existing tests passed.

[welcome]

Thanks for opening this pull request! Please check out our contributing guidelines! ⛰️

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 41.38%. Comparing base (c7001e9) to head (060c84d).
Report is 1 commits behind head on main.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #608      +/-   ##
==========================================
+ Coverage   41.27%   41.38%   +0.11%     
==========================================
  Files          15       15              
  Lines        1071     1073       +2     
==========================================
+ Hits          442      444       +2     
  Misses        629      629              

Flag	Coverage Δ
unit-tests	41.38% <100.00%> (+0.11%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[orhun]

Perfect, thank you! 🐻

[welcome]

Congrats on merging your first pull request! ⛰️