fix(remote): preserve first time contributors

[mcwarman]

Description

Preserve first time contributors in older change logs

Fixes #891

Motivation and Context

When a new release is created and all change logs regenerated the first time contributor section is removed.

How Has This Been Tested?

Tested using existing fixtures.

Types of Changes

• [x] 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:

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