* docker.io/library/golang from 1.22 to 1.23
* gotestsum from 0.4.2 to 1.12.0
* protoc-gen-go from 1.28.1 to 1.35.2
* protoc-gen-go-grpc from 1.2 to 1.5.1
* docker.io/library/rust from 1.76.0 to 1.83.0
* cargo-deny from 0.14.11 to 0.16.3
* cargo-nextest from 0.9.67 to 0.9.85
* cargo-tarpaulin from 0.27.3 to 0.31.3
* just from 1.24.0 to 1.37.0
* yq from 4.33.3 to 4.44.5
* markdownlint-cli2 from 0.10.0 to 0.15.0
* shellcheck from 0.9.0 to 0.10.0
* actionlint from 1.6.26 to 1.7.4
* protoc from 3.20.3 to 29.0
* step from 0.25.2 to 0.28.2
* kubectl from 1.29.2 to 1.31.3
* k3d from 5.6.0 to 5.7.5
* k3s image shas
* helm from 3.14.1 to 3.16.3
* helm-docs from 1.12.0 to 1.14.2
* Update dev to v42
* Update Rust to 1.73.0
* Address new clippy & check warnings
* Update debian from bullseye to bookworm
* Update K3d to v5.6.0
* Update CI from k3s 1.26 to 1.28
* Fix `just linkerd-install` to specify k8s context
* Update markdownlint-cli2 to 0.10.0
* Update Dockerfile to use a debian base image for easier debugging
* Update proc-macro2 to fix rust-nightly build failures
* chore: change `rust-toolchain` file to toml format
The `rust-toolchain` file containing only a Rust version number is
deprecated in favor of a TOML-formatted `rust-toolchain.toml`. Using the
old format seems to make Dependabot unhappy --- it complains that:
```
only rust-toolchain files formatted as TOML are supported, the non-TOML
format was deprecated by Rust
```
Therefore, this branch changes the toolchain file in this repo to the
TOML format. This required updating the CI workflows that check that
the toolchain matches to use a new regex.
Oliver Gould