Fix identical yaml hidden key in CI templates

This was causing DAST to clobber Deploy's key.

The DAST hidden key should not affect the Deploy template hidden key.
This allows a template to be updated independently of each other.

lib/gitlab/ci/templates/Jobs/DAST-Default-Branch-Deploy.gitlab-ci.yml

-.auto-deploy:
+.dast-auto-deploy:
   image: "registry.gitlab.com/gitlab-org/cluster-integration/auto-deploy-image:v0.4.0"
 
 dast_environment_deploy:
-  extends: .auto-deploy
+  extends: .dast-auto-deploy
   stage: review
   script:
     - auto-deploy check_kube_domain
@@ -31,7 +31,7 @@ dast_environment_deploy:
       - $DAST_WEBSITE # we don't need to create a review app if a URL is already given
 
 stop_dast_environment:
-  extends: .auto-deploy
+  extends: .dast-auto-deploy
   stage: cleanup
   variables:
     GIT_STRATEGY: none