Configure SAST in `.gitlab-ci.yml`, creating this file if it does not already exist

.gitlab-ci.yml

@@ -1,12 +1,20 @@
----
+# You can override the included template(s) by including variable overrides
+# SAST customization: https://docs.gitlab.com/ee/user/application_security/sast/#customizing-the-sast-settings
+# Secret Detection customization: https://docs.gitlab.com/ee/user/application_security/secret_detection/#customizing-settings
+# Dependency Scanning customization: https://docs.gitlab.com/ee/user/application_security/dependency_scanning/#customizing-the-dependency-scanning-settings
+# Note that environment variables can be set in several places
+# See https://docs.gitlab.com/ee/ci/variables/#cicd-variable-precedence
 variables:
-    DOCKER_BUILD_TEST_BUILD_FILE: devops/docker/php/Dockerfile
-    DOCKER_BUILD_TEST_TARGET: test
-    DOCKER_RELEASE_BUILD_FILE: devops/docker/php/Dockerfile
-    DOCKER_RELEASE_BUILD_TARGET: test
-
+  DOCKER_BUILD_TEST_BUILD_FILE: devops/docker/php/Dockerfile
+  DOCKER_BUILD_TEST_TARGET: test
+  DOCKER_RELEASE_BUILD_FILE: devops/docker/php/Dockerfile
+  DOCKER_RELEASE_BUILD_TARGET: test
 include:
-    - project: infra/kernel/ci-templates
-      ref: master
-      file: /${CI_PROJECT_PATH}.yml
-...
+- project: infra/kernel/ci-templates
+  ref: master
+  file: "/${CI_PROJECT_PATH}.yml"
+- template: Security/SAST.gitlab-ci.yml
+stages:
+- test
+sast:
+  stage: test