feat: implicitly enable vpc access when using cloudsql

mentioned in merge request example-service!176 (merged)

mentioned in merge request docs!107 (merged)

mentioned in merge request gitlab-org/modelops/applied-ml/code-suggestions/ai-assist!1817 (merged)

mentioned in merge request docs!111 (merged)

mentioned in merge request gitlab-org/security-products/secret-detection/secret-detection-service!70 (closed)

mentioned in merge request gitlab-org/security-products/secret-detection/secret-detection-service!78 (merged)