(bugfix): fix a bug in the containers image source

where we always pulled image references using the canonical reference.
Now we pull images using the reference provided to the source. Using only
the canonical reference resulted in not respecting some mirroring configurations
related to tags because we never used tag-based references.

Signed-off-by: everettraven <everettraven@gmail.com>

internal/rukpak/source/containers_image.go

@@ -80,7 +80,7 @@ func (i *ContainersImageRegistry) Unpack(ctx context.Context, bundle *BundleSour
 	// copy.Image can concurrently pull all the layers.
 	//
 	//////////////////////////////////////////////////////
-	dockerRef, err := docker.NewReference(canonicalRef)
+	dockerRef, err := docker.NewReference(imgRef)
 	if err != nil {
 		return nil, fmt.Errorf("error creating source reference: %w", err)
 	}