fix: cache key for trivy

mentioned in commit a4ce3930

mentioned in merge request to-be-continuous/samples/maven-on-openshift!99

mentioned in merge request to-be-continuous/samples/maven-on-gcloud!154 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-kubernetes!155

mentioned in merge request to-be-continuous/samples/maven-library!52 (closed)

mentioned in merge request to-be-continuous/samples/maven-library!53 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-openshift!101 (merged)

mentioned in merge request to-be-continuous/samples/maven-on-kubernetes!158 (merged)

mentioned in merge request d3269/tbc-cicd-for-java!18