Placeholder file to allow git to track this directory. This allows us to use go:embed of the directory in the test file without causing compilation issues when using go tools outside of bazel. Please note the test won't run successfully when using any tools outside of bazel as bazel populates this directory during build time. We don't use `write_source_files` to populate this directory as this would break the direct dependency between the test and the source manifests/container_push rule, causing potentially stale data to be used in tests when running locally.