use trivy mirror for 0 rate limiting

A solution to Trivy Rate Limiting Error described in Runner intermittent failures (#127 - closed)

.gitlab-ci.yml

@@ -204,8 +204,8 @@ Build Docker Image:
       --build-arg GIT_COMMIT_SHA=${CI_COMMIT_SHA}
       --tag "${LOCAL_IMAGE}"
       "."
-
     ## trivy scan before push
+    - export TRIVY_DB_REPOSITORY=mirror.gcr.io/aquasec/trivy-db #Trivy looks for this variable to determine which repository to use. Only one allowed until trivy >= 0.56
     # fail LOW,MEDIUM vulnerabilities that have a fix available
     - trivy image --exit-code 1 --ignore-unfixed --severity LOW,MEDIUM "${LOCAL_IMAGE}";
     # fail HIGH,CRITICAL vulnerabilities