Remove data-platform environment

We are no longer using any of this.

It also came with a customisation to the standard github actions
workflow which we wanted to remove.
ministryofjustice/data-catalogue#60

.github/CODEOWNERS

@@ -18,7 +18,6 @@
 /terraform/environments/data-and-insights-wepi @ministryofjustice/data-and-insights-hub @ministryofjustice/modernisation-platform
 /terraform/environments/data-platform-apps-and-tools @ministryofjustice/data-platform-apps-and-tools @ministryofjustice/modernisation-platform
 /terraform/environments/data-platform-compute @ministryofjustice/data-platform-apps-and-tools @ministryofjustice/modernisation-platform
-/terraform/environments/data-platform @ministryofjustice/data-platform-apps-and-tools @ministryofjustice/data-platform-labs @ministryofjustice/modernisation-platform
 /terraform/environments/delius-core @ministryofjustice/hmpps-migration @ministryofjustice/modernisation-platform
 /terraform/environments/delius-iaps @ministryofjustice/hmpps-dba @ministryofjustice/hmpps-migration @ministryofjustice/modernisation-platform
 /terraform/environments/delius-jitbit @ministryofjustice/hmpps-delius-jitbit-devs @ministryofjustice/hmpps-migration @ministryofjustice/modernisation-platform

.github/dependabot.yml

@@ -1,4 +1,4 @@
-# This file is auto-generated here, do not manually amend. 
+# This file is auto-generated here, do not manually amend.
 # scripts/generate-dependabot.sh
 
 version: 2
@@ -105,10 +105,6 @@ updates:
     directory: "/terraform/environments/data-and-insights-wepi"
     schedule:
       interval: "daily"
-  - package-ecosystem: "terraform"
-    directory: "/terraform/environments/data-platform"
-    schedule:
-      interval: "daily"
   - package-ecosystem: "terraform"
     directory: "/terraform/environments/data-platform-apps-and-tools"
     schedule: