submodule: bump openthread from `7e2b694` to `3726888` (#182)
submodule: bump openthread from `7e2b694` to `3726888` (#182)

Bumps [openthread](https://github.com/openthread/openthread) from `7e2b694` to `3726888`.
- [Commits](https://github.com/openthread/openthread/compare/7e2b694c1d68813cf1ebd2703d4f0e88267c76bb...37268889370467c5e48e306d322472d6910ebb13)

---
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-cc2538,openthread/ot-cc2538