Next rustc-toolchain update?

It has been almost 11 months since the next toolchain update, and we will soon be forced to update it due to other dependencies.

Hence, I would like to ask for a toolchain update. :)

The issue names no files, tests, or target toolchain version. Start by locating the repository's Rust toolchain configuration and dependency manifests, then check which dependency requires an update; done means the toolchain is updated and the project builds and tests successfully.

Written by the indexing model from the issue text.