v3.1.5

Improvement (#129)

* Guard runtime-args offset against overflow and update deps

- Add explicit checks to ensure the runtime arguments offset does not exceed UINT8_MAX before casting, preventing potential truncation issues in TransactionV1 parsing.
- Update the ledger-zxlib subproject to the latest version.

* Bump version to 3.1.5 and update Zemu snapshots

- Increment patch version to 3.1.5 in Makefile.version.
- Refresh main menu snapshots for all device models to reflect the version change.