submodule: bump third_party/openthread/repo from c6b120e to ed62353 (#3175)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `c6b120e` to `ed62353`.
- [Commits](openthread/openthread@c6b120e...ed62353)

---
updated-dependencies:
- dependency-name: third_party/openthread/repo
  dependency-version: ed6235304b4380eccc483d962e425370ae4cabcc
  dependency-type: direct:production
...

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Author: dependabot[bot]