Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Add a new argument --preserve-mtime to keep the original modified time attribute of notes being exported, instead of setting them to the current time.
Various semi-related changes to the GHA setup to maximize code-reuse and cache effectiveness, as well as introduce rust-toolchain.toml and cargo deny.