build(deps): bump github.com/containers/storage from 1.15.7 to 1.15.8

Bumps [github.com/containers/storage](https://github.com/containers/storage) from 1.15.7 to 1.15.8.
- [Release notes](https://github.com/containers/storage/releases)
- [Changelog](https://github.com/containers/storage/blob/master/docs/containers-storage-changes.md)
- [Commits](https://github.com/containers/storage/compare/v1.15.7...v1.15.8)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/containers/storage/pkg/archive/diff.go

@@ -68,7 +68,7 @@ func UnpackLayer(dest string, layer io.Reader, options *TarOptions) (size int64,
 		// specific or Linux-specific, this warning should be changed to an error
 		// to cater for the situation where someone does manage to upload a Linux
 		// image but have it tagged as Windows inadvertently.
-		if runtime.GOOS == "windows" {
+		if runtime.GOOS == windows {
 			if strings.Contains(hdr.Name, ":") {
 				logrus.Warnf("Windows: Ignoring %s (is this a Linux image?)", hdr.Name)
 				continue