`csnx` → `dotcom-rendering`

[sndrs]

Following #9865, @guardian/client-side-infra plan to move the libs that currently live in https://github.com/guardian/csnx to this repo.

As part of this, CSTI will also start to take a more active repo maintaining role.

This issue tracks the changes to make that happen.

### Tasks
- [x] raise RFC in https://github.com/guardian/dotcom-rendering/discussions
- [x] agreement between @guardian/client-side-infra and @guardian/dotcom-platform on proceeding (or not)
- [ ] https://github.com/guardian/dotcom-rendering/issues/10110
- [ ] https://github.com/guardian/csnx/pull/1404
- [ ] https://github.com/guardian/csnx/issues/1418
- [ ] https://github.com/guardian/csnx/issues/1430
- [ ] enable task caching in `dotcom-rendering`
- [ ] enable publishing to npm in `dotcom-rendering`
- [ ] Consider how to handle backlogs of unpublished changes to packages consumed directly by DCR
- [ ] move `@guardian/source-react-components-development-kitchen` to `dotcom-rendering`
- [ ] move `@guardian/source-react-components` to `dotcom-rendering`
- [ ] Publish `@guardian/design-tokens`
- [ ] move `@guardian/source-foundations` to `dotcom-rendering`
- [ ] rename `guardian/dotcom-rendering` repo?
- [ ] move `@guardian/design-tokens` to `dotcom-rendering`
- [ ] move `@guardian/eslint-plugin-source-foundations` to `dotcom-rendering`
- [ ] move `@guardian/eslint-plugin-source-react-components` to `dotcom-rendering`
- [ ] move `@guardian/libs` to `dotcom-rendering`
- [ ] move `@guardian/core-web-vitals` to `dotcom-rendering`
- [ ] move `@guardian/identity-auth` to `dotcom-rendering`
- [ ] move `@guardian/identity-auth-frontend` to `dotcom-rendering`
- [ ] move `@guardian/ab-core` to `dotcom-rendering`
- [ ] move `@guardian/ab-react` to `dotcom-rendering`
- [ ] move `@guardian/tsconfig` to `dotcom-rendering`
- [ ] move `@guardian/browserslist-config` to `dotcom-rendering`
- [ ] move `@guardian/eslint-config` to `dotcom-rendering`
- [ ] move `@guardian/eslint-config-typescript` to `dotcom-rendering`
- [ ] https://github.com/guardian/dotcom-rendering/issues/10404
- [ ] move `@guardian/newsletter-types` to...?
- [ ] archive `csnx`