…6.1 everywhere

# Conflicts:
#	pixi.toml

### What
 - Switch to using docker buildx to create the docker environment
- Update the platform-specific parts of the dockerfile to use the
targetplatform
 - Bump the version to 0.12 just in case something goes wrong.
 - Start using the docker container on buildjet

```
$ docker buildx imagetools inspect  rerunio/ci_docker:0.12.0
Name:      docker.io/rerunio/ci_docker:0.12.0
MediaType: application/vnd.oci.image.index.v1+json
Digest:    sha256:9575a44a30152ef292c8f73e9546f1d431ea32246bc7a0043ba51f4df936c537
           
Manifests: 
  Name:        docker.io/rerunio/ci_docker:0.12.0@sha256:7e0e5a31234578d10c53733e9e703972d73ac7df992323d95feb60700cb94e4b
  MediaType:   application/vnd.oci.image.manifest.v1+json
  Platform:    linux/arm64
               
  Name:        docker.io/rerunio/ci_docker:0.12.0@sha256:e1861e823b15b3accf103c00910fa24a89aa274f02550b5458524322cc1f39ce
  MediaType:   application/vnd.oci.image.manifest.v1+json
  Platform:    linux/amd64
```

Successful buildjet run:
https://github.com/rerun-io/rerun/actions/runs/8301499563/job/22721760001

![image](https://github.com/rerun-io/rerun/assets/3312232/8524e28e-8630-4c1e-a0e1-972e5a928487)


### 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/5543/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5543/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/5543/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/5543)
- [Docs
preview](https://rerun.io/preview/3eb7524e2f955e97dcb423b6a16c10f7fdb75ba9/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/3eb7524e2f955e97dcb423b6a16c10f7fdb75ba9/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

This reverts commit 2a4092e.

# Conflicts:
#	.github/workflows/reusable_test_wheels.yml