Update test files

• Removes multi.yml to avoid redundancy. Relevant discussion: gitlab-org/security-products/analyzers/kubesec!77 (comment 1187028663)

• Update the test files due to update in Kubesec version. The Kubesec version directly drives the schema version used to verify files to be scanned. Related discussion: gitlab-org/security-products/analyzers/kubesec!80 (comment 1236983947)

This will help in fixing the QA pipeline job failures as well https://gitlab.com/gitlab-org/security-products/tests/kubernetes/-/pipelines?page=1&scope=all&status=failed&username=willmeek