Remove CDK and CI for Apps Rendering (#14868)

* Remove CDK and AR infrastructure

* Remove Riff-Raff config

* Remove AR CI workflow

* Remove CDK references from config files

* Remove AR from check node version script

Author: jamesmockett

.github/workflows/ar-ci.yml

@@ -2,4 +2,3 @@
 node_modules
 api-models
 webpack.config.ts
-cdk.out

apps-rendering/.eslintignore

@@ -25,7 +25,3 @@ dist
 
 # Istanbul/Jest code coverage
 coverage
-
-# CDK asset staging directory
-.cdk.staging
-cdk.out