Weird character showing up during automation of GitHub PR changelog

I’m using a workflow to automate the creation of a changelog when a PR is open.

Basically, I’m fetching all the commits in a PR and updating the PR body to look something like this:

Changelog:
- feat: new file
- feat: update to file

However, along the way something weird is happening and this is what I see in the output:

Not sure where this arrow is coming from.

For clarity, this is what the code looks like:

          const commitMessages = `${{ steps.fetch-commits.outputs.commit_messages }}`;
          let changelog = "## Changelog:n";
          
          commitMessages.split('|').forEach(line => {
            changelog += `${line}`;
          });
          
          const prNumber = context.payload.pull_request.number;
          const owner = context.repo.owner;
          const repo = context.repo.repo;
          
          await github.rest.pulls.update({
            owner: owner,
            repo: repo,
            pull_number: prNumber,
            body: changelog,
            headers: {
              authorization: `token ${process.env.PAT}`
            }
          });