submodule: bump openthread from 33a1f09 to 0019f38

Bumps [openthread](https://github.com/openthread/openthread) from `33a1f09` to `0019f38`.
- [Release notes](https://github.com/openthread/openthread/releases)
- [Commits](openthread/openthread@33a1f09...0019f38)

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

Signed-off-by: dependabot[bot] <[email protected]>