submodule: bump third_party/openthread/repo from `5edb9fb` to `5c8c318` (#3574)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `5edb9fb` to `5c8c318`.
- [Commits](https://github.com/openthread/openthread/compare/5edb9fbb0be399db40760fd0115f830d364bc8e1...5c8c318627954c99cd1a957a290bbd4b1027d04b)

---
updated-dependencies:
- dependency-name: third_party/openthread/repo
  dependency-version: 5c8c318627954c99cd1a957a290bbd4b1027d04b
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
diff --git a/third_party/openthread/repo b/third_party/openthread/repo
index 5edb9fb..5c8c318 160000
--- a/third_party/openthread/repo
+++ b/third_party/openthread/repo
@@ -1 +1 @@
-Subproject commit 5edb9fbb0be399db40760fd0115f830d364bc8e1
+Subproject commit 5c8c318627954c99cd1a957a290bbd4b1027d04b