submodule: bump openthread from 650e30f to e958f88 (#620)

Bumps [openthread](https://github.com/openthread/openthread) from `650e30f` to `e958f88`.
- [Commits](openthread/openthread@650e30f...e958f88)

---
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>