submodule: bump third_party/openthread/repo from e029417 to `49c59e…

…c` (#2193)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `e029417` to `49c59ec`.
- [Commits](openthread/openthread@e029417...49c59ec)

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

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