submodule: bump openthread from `a8924f6` to `2057ca8` (#301)
submodule: bump openthread from `a8924f6` to `2057ca8` (#301)

Bumps [openthread](https://github.com/openthread/openthread) from `a8924f6` to `2057ca8`.
- [Commits](https://github.com/openthread/openthread/compare/a8924f65f78db30a9825653966051a07412aed9e...2057ca8846ae0d029ab26063bba3d39906aaa071)

---
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-samr21,openthread/ot-samr21