build(deps): bump github.com/Microsoft/hcsshim from 0.8.20 to 0.9.6

Bumps [github.com/Microsoft/hcsshim](https://github.com/Microsoft/hcsshim) from 0.8.20 to 0.9.6.
- [Release notes](https://github.com/Microsoft/hcsshim/releases)
- [Commits](https://github.com/Microsoft/hcsshim/compare/v0.8.20...v0.9.6)

---
updated-dependencies:
- dependency-name: github.com/Microsoft/hcsshim
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>

vendor/github.com/Microsoft/hcsshim/internal/wclayer/unpreparelayer.go

@@ -19,7 +19,7 @@ func UnprepareLayer(ctx context.Context, path string) (err error) {
 
 	err = unprepareLayer(&stdDriverInfo, path)
 	if err != nil {
-		return hcserror.New(err, title+" - failed", "")
+		return hcserror.New(err, title, "")
 	}
 	return nil
 }