Roll Rsnap dependencies

[yvette-carlisle]

Summary

• Refresh Cargo.lock to the latest Rust 1.96.0-compatible dependency graph.
• Roll actions/checkout from v6.0.2 to v6.0.3 and keep full-SHA pins.
• Roll taiki-e/install-action from v2.79.4 to v2.81.11 and keep full-SHA pins.

Provenance

• actions/checkout v6.0.3 -> df4cb1c069e1874edd31b4311f1884172cec0e10
• taiki-e/install-action v2.81.11 -> 15449e3094499af05d8d964a1c884208e4b8b595

Validation

• cargo make fmt-toml-check
• actionlint
• cargo make check-rust
• cargo make test-rust (682 passed)
• cargo update --dry-run (0 packages pending for Rust 1.96.0)