chore: add dependency images-essential -> images

This is needed to make sure that those steps don't run in parallel on
release builds, as they write same output files.

Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>

.drone.jsonnet

@@ -540,7 +540,7 @@ local conformance_pipelines = [
 // Release pipeline.
 
 local cloud_images = Step("cloud-images", depends_on=[e2e_docker, e2e_qemu], environment=creds_env_vars);
-local images = Step("images", target="images", depends_on=[iso], environment={"IMAGE_REGISTRY": local_registry});
+local images = Step("images", target="images", depends_on=[iso, images_essential], environment={"IMAGE_REGISTRY": local_registry});
 local sbcs = Step("sbcs", target="sbcs", depends_on=[images], environment={"IMAGE_REGISTRY": local_registry});
 
 // TODO(andrewrynhard): We should run E2E tests on a release.