Remove what's left of setup_dev.sh & setup.sh (#5552)

### What

Almost everything has been taken over by `pixi` by now and these
outdated / partially broken scripts keep confusing new-comers to the
repo, so at this point they're clearly doing more bad than good.

* Fixes #5545
* Fixes #4170
* There's still some stuff that should be moved to pixi but that's
better covered by #3717


### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/5552/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5552/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/5552/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5552)
- [Docs
preview](https://rerun.io/preview/8da4ef3b503b5459274c73ea40bc0926b61dbae9/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/8da4ef3b503b5459274c73ea40bc0926b61dbae9/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

---------

Co-authored-by: Emil Ernerfeldt <[email protected]>

BUILD.md

@@ -23,12 +23,6 @@ cd rerun
 
 Now install the `pixi` package manager: <https://github.com/prefix-dev/pixi?tab=readme-ov-file#installation>
 
-Finally, run the following script to install the dependencies and CLI tools needed for Rerun's build environment:
-
-```sh
-./scripts/setup_dev.sh
-```
-
 Make sure `cargo --version` prints `1.74.0` once you are done.
 
 If you are using an Apple-silicon Mac (M1, M2), make sure `rustc -vV` outputs `host: aarch64-apple-darwin`. If not, this should fix it:
@@ -37,6 +31,14 @@ If you are using an Apple-silicon Mac (M1, M2), make sure `rustc -vV` outputs `h
 rustup set default-host aarch64-apple-darwin && rustup install 1.74.0
 ```
 
+Additionally, we use [cargo-cranky](https://github.com/ericseppanen/cargo-cranky) for defining which Clippy lints are active and [cargo-deny](https://github.com/EmbarkStudios/cargo-deny) for linting crate versions.
+You don't need to install these for building, but it's highly recommended when contributing changes to
+Rust code.
+```sh
+cargo install cargo-cranky
+cargo install --locked cargo-deny
+```
+
 ## Building and running the viewer
 
 Use this command for building and running the viewer:

ci_docker/Dockerfile

@@ -6,7 +6,6 @@ LABEL version="0.11.0"
 LABEL description="Docker image used for the CI of https://github.com/rerun-io/rerun"
 
 # Install the ubuntu package dependencies
-# This mirrors scripts/setup.sh
 ENV DEBIAN_FRONTEND=noninteractive
 RUN set -eux; \
     apt-get update; \