using --latest flag always detects new contributors (that are not new)

Is there an existing issue for this?

• I have searched the existing issues

Description of the bug

Hello team

I have a bug with git cliff, when using it to generate the release body, I always have new contributors popping, even if they have been contributing for a while.

Steps To Reproduce

I run this to draft the release (in a github workflow):

 git cliff \
 -vv --latest --unreleased --strip all -o CHANGES.md \
 --github-repo ${{ github.repository }} \
 --github-token ${{ secrets.GITHUB_TOKEN }} \
 --tag ${{ inputs.tag }}

Expected behavior

Expected behavior is to detect new contributors, only when there are new contributors

Screenshots / Logs

N/A

Software information

I run the latest version of git cliff in my github actions (github runner: ubuntu latest)

Additional context

The command for changelog with the same config works fine.

git cliff \
 --verbose --strip 'footer' -o CHANGELOG.md \
 --github-repo ${{ github.repository }} \
 --github-token ${{ secrets.GITHUB_TOKEN }} \
 --tag ${{ inputs.tag }}

Thank you very much for your help