Update SAST.gitlab-ci.yml - Add SAST_GITLEAKS_ENTROPY_LEVEL

This env was missing, causing the variable to not
be propagated to child containers and thus, be ineffective

changelogs/unreleased/patch-64.yml

+---
+title: Update SAST.gitlab-ci.yml - Add SAST_GITLEAKS_ENTROPY_LEVEL
+merge_request: 28607
+author:
+type: fixed

lib/gitlab/ci/templates/Security/SAST.gitlab-ci.yml

@@ -40,6 +40,7 @@ sast:
           SAST_BRAKEMAN_LEVEL \
           SAST_GOSEC_LEVEL \
           SAST_FLAWFINDER_LEVEL \
+          SAST_GITLEAKS_ENTROPY_LEVEL \
           SAST_DOCKER_CLIENT_NEGOTIATION_TIMEOUT \
           SAST_PULL_ANALYZER_IMAGE_TIMEOUT \
           SAST_RUN_ANALYZER_TIMEOUT \