Update c/image for golang.org/x/exp

> go get github.com/containers/image/v5@main
> go mod tidy && go mod vendor

This updates c/image with a new version of x/exp.
That package has changed API in an incompatible way,
so just bumping x/exp (as in https://github.com/containers/skopeo/pull/2060 )
would break Skopeo builds.

This updates both c/image and x/exp in lockstep (and nothing
needs updating in Skopeo itself for the x/exp breakage).

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/github.com/vbauerster/mpb/v8/bar_option.go

@@ -15,11 +15,6 @@ func inspect(decorators []decor.Decorator) (dest []decor.Decorator) {
 		if decorator == nil {
 			continue
 		}
-		if d, ok := decorator.(interface {
-			PlaceHolders() []decor.Decorator
-		}); ok {
-			dest = append(dest, d.PlaceHolders()...)
-		}
 		dest = append(dest, decorator)
 	}
 	return
@@ -93,10 +88,10 @@ func BarFillerOnComplete(message string) BarOption {
 
 // BarFillerMiddleware provides a way to augment the underlying BarFiller.
 func BarFillerMiddleware(middle func(BarFiller) BarFiller) BarOption {
+	if middle == nil {
+		return nil
+	}
 	return func(s *bState) {
-		if middle == nil {
-			return
-		}
 		s.filler = middle(s.filler)
 	}
 }