remove the old source tracker code

scripts/deno/source-tracker/README.md

@@ -1,21 +1,3 @@
 # `@guardian/source-*` package usage tracker
 
-This Deno script is used to track the usage of the `@guardian/source-*` packages in the Guardian GitHub organisation.
-
-It keeps https://github.com/guardian/csnx/issues/1058 up to date.
-
-## Development
-
-You can run it locally by running `deno run -A scripts/deno/source-tracker/mod.ts`.
-
-You will need to create a personal access token at https://github.com/settings/tokens/new?scopes=repo and add it to an `.env` file as `GITHUB_TOKEN`.
-
-### Local caching
-
-To avoid hitting the rate limit in dev, the script saves the responses from the APIs it hits in Deno's `localStorage`.
-
-If you want to clear/disable that, uncomment the `localStorage.clear()` line in `mod.ts`.
-
-## Production
-
-The script is run once a day by a GitHub Action. See `.github/workflows/source-tracker.yml`.
+This script has been superseded by [the `package-tracker` script in `guardian/CSTI-team`](https://github.com/guardian/CSTI-team/tree/main/scripts/package-tracker).