third_party/sandboxroot/mirror: fix %v in cases where we should use %w

Change-Id: I567a61c3c7fc790f586d6214f5275f1fd06c1180
Reviewed-on: https://review.monogon.dev/c/monogon/+/3094
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/third_party/sandboxroot/mirror/bazeldnf.go b/third_party/sandboxroot/mirror/bazeldnf.go
index 4f85581..1a2f5ec 100644
--- a/third_party/sandboxroot/mirror/bazeldnf.go
+++ b/third_party/sandboxroot/mirror/bazeldnf.go
@@ -36,7 +36,7 @@
 
 		ext, err := newRPMDef(name.GoString(), sha256.GoString(), urlsS)
 		if err != nil {
-			return nil, fmt.Errorf("invalid rpm: %v", err)
+			return nil, fmt.Errorf("invalid rpm: %w", err)
 		}
 		res = append(res, ext)
 		return starlark.None, nil