Bump iqtree3 from 42f595b to 5a60dad

Bumps [iqtree3](https://github.com/iqtree/iqtree3) from `42f595b` to `5a60dad`.
- [Release notes](https://github.com/iqtree/iqtree3/releases)
- [Commits](iqtree/iqtree3@42f595b...5a60dad)

---
updated-dependencies:
- dependency-name: iqtree3
  dependency-version: 5a60dad9e09126b9a35ede1cd75b90d2ff84b93a
  dependency-type: direct:production
...

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Author: dependabot[bot]