submodule: bump openthread from 6edb06e to 0f55e79 (#608)

Bumps [openthread](https://github.com/openthread/openthread) from `6edb06e` to `0f55e79`.
- [Commits](openthread/openthread@6edb06e...0f55e79)

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

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