Bump Fronter from 66c9f45 to d3603b6 (#582)

Bumps [Fronter](https://github.com/ParadoxGameConverters/Fronter) from `66c9f45` to `d3603b6`.
- [Commits](ParadoxGameConverters/Fronter@66c9f45...d3603b6)

---
updated-dependencies:
- dependency-name: Fronter
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>