submodule: bump openthread from `8e9d58f` to `8769898`

[dependabot[bot]]

Bumps openthread from 8e9d58f to 8769898.

Commits

• 8769898 [tests] fix test_manual_maddress.py (#9923)
• ec7781a [thread-cert] set device mode in test_mle_msg_key_seq_jump (#9921)
• 2e24098 [posix] add IPv6 address helper functions in Ip6Utils (#9917)
• be06d7c [daemon] always initialize the OT CLI when setting up the daemon (#9919)
• See full diff in compare view

You can trigger a rebase of this PR by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot show ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)