submodule: bump third_party/openthread/repo from `4a7c447` to `4e83caf` (#1614)
submodule: bump third_party/openthread/repo from `4a7c447` to `4e83caf` (#1614)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `4a7c447` to `4e83caf`.
- [Commits](https://github.com/openthread/openthread/compare/4a7c447f6c381ee6f695371c8b20dcc2be895211...4e83caf42d8d3f30798523a53dfbad4ff15cfdc8)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/ot-br-posix