Remove reference to the govuk data tool

This repo has been retired and we are not able to use it anymore
to import data.

docs/import_production_data.md

@@ -2,22 +2,3 @@
 
 To import production data, follow the instructions for
 [govuk-docker](https://github.com/alphagov/govuk-docker#how-to-replicate-data-locally)
-
-## Using the `govuk data` tool
-
-It's also possible to import data for the Content Performance Manager
-using the experimental [`govuk data`][govuk-data-docs] tool.
-
-[govuk-data-docs]: https://github.com/alphagov/govuk-guix/blob/master/doc/local-data.md
-
-To see what data is available, run:
-
-```
-govuk data list content-data-api
-```
-
-To load the default extract, run:
-
-```
-govuk data load content-data-api
-```