submodule: bump openthread from `a422069` to `137c401` (#5)
submodule: bump openthread from `a422069` to `137c401` (#5)

Bumps [openthread](https://github.com/openthread/openthread) from `a422069` to `137c401`.
- [Commits](https://github.com/openthread/openthread/compare/a4220690ee398b95ce46b3f7b42ccbfeee0d55dd...137c40136cab33eaa32066223f0a1b4838ed225d)

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

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

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-ifx,openthread/ot-ifx,openthread/ot-ifx,Infineon/ot-ifx-release,Infineon/ot-ifx-release,Infineon/ot-ifx-release