Use CS_ANALYZER_IMAGE in CS template

changelogs/unreleased/reference-cs-image-in-template.yml

+---
+title: Use CS_ANALYZER_IMAGE in CS template
+merge_request: 47856
+author:
+type: added

lib/gitlab/ci/templates/Security/Container-Scanning.gitlab-ci.yml

@@ -8,7 +8,7 @@ variables:
 
 container_scanning:
   stage: test
-  image: $SECURE_ANALYZERS_PREFIX/klar:$CS_MAJOR_VERSION
+  image: "$CS_ANALYZER_IMAGE"
   variables:
     # By default, use the latest clair vulnerabilities database, however, allow it to be overridden here with a specific image
     # to enable container scanning to run offline, or to provide a consistent list of vulnerabilities for integration testing purposes
@@ -18,6 +18,7 @@ container_scanning:
     # file. See https://docs.gitlab.com/ee/user/application_security/container_scanning/index.html#overriding-the-container-scanning-template
     # for details
     GIT_STRATEGY: none
+    CS_ANALYZER_IMAGE: $SECURE_ANALYZERS_PREFIX/klar:$CS_MAJOR_VERSION
   allow_failure: true
   services:
     - name: $CLAIR_DB_IMAGE