Bump third_party/openthread/repo from d4155e4 to 5f8f05c

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `d4155e4` to `5f8f05c`.
- [Release notes](https://github.com/openthread/openthread/releases)
- [Commits](openthread/openthread@d4155e4...5f8f05c)

---
updated-dependencies:
- dependency-name: third_party/openthread/repo
  dependency-type: direct:production
...

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