fix(ci): remove --all flag from skopeo copy to fix registry push

skopeo copy --all is designed for multi-arch manifest lists. When the
source OCI archive is a single-arch image (as built here without
--platform), newer versions of skopeo can fail with --all since the
source is not a proper manifest list. Removing --all lets skopeo copy
the single image directly to the registry.

https://claude.ai/code/session_01EPCuwhfNsPPDS5KCduYZfb

Author: claude

.github/workflows/release.yaml

@@ -109,16 +109,16 @@ jobs:
           fi
 
           # Push semantic version tag (1.2.3)
-          skopeo copy --all "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${IMAGE_VERSION}"
+          skopeo copy "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${IMAGE_VERSION}"
 
           # Push major.minor tag (1.2)
-          skopeo copy --all "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${MAJOR}.${MINOR}"
+          skopeo copy "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${MAJOR}.${MINOR}"
 
           # Push major tag (1)
-          skopeo copy --all "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${MAJOR}"
+          skopeo copy "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:${MAJOR}"
 
           # Push latest tag
-          skopeo copy --all "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:latest"
+          skopeo copy "oci-archive:build/${IMAGE_NAME}.tar" "docker://${REGISTRY}:latest"
 
       - name: Verify pushed image
         env: