[chore] Clean up rapidfuzz dupe checking logic to be more concise

[scottnemes]

Description

Simplifies the rapidfuzz dupe checking logic to be more concise.

Checklist

• I added this contribution to the changelog.md file.
• I added my name to the AUTHORS file (or it's already there).
• To lint and format the code, I ran

  uv run ruff check && uv run ruff format && uv run mypy --install-types .

[scottnemes]

@rolandwalker I'm looking for areas that can be cleaned up to reduce code size / complexity where possible. If this (or any future ones) are something you don't think should happen, feel free to close it. Looking at small(ish) pieces to reduce any impact / review complexity.