submodule: bump openthread from 3b30c84 to a05954b (#684)

Bumps [openthread](https://github.com/openthread/openthread) from `3b30c84` to `a05954b`.
- [Commits](openthread/openthread@3b30c84...a05954b)

---
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>