zabbix: bump version to 7.0.31 - #30699

Checking PR #30699: zabbix: bump version to 7.0.31 (Formalities Audit)

✅ Pull request originates from a dedicated feature branch (pr-zabbix-bump-to-7-0-31)

Commit d6f1df9 - zabbix: bump version to 7.0.31:

✅ Author and committer identities are valid
✅ Commit is not a merge commit
✅ Commit subject layout and length are valid: "zabbix: bump version to 7.0.31"
✅ Commit description lines adhere to width formatting rules
✅ Commit contains a valid 'Signed-off-by:' line matching author or committer
⚠️ Warning: Commit is unsigned or cryptographic signature verification failed (Reason: unsigned). Signing commits is a recommended best practice for verifying identity, but is not mandatory.