Fix Tagging XML Unmarshalling (#8977)

AWS S3 doesn't strictly enforce the presence of URL in tagging XML.
This PR updates MinIO to behave similarly.

Fixes #8976

pkg/bucket/object/tagging/tagging.go

@@ -41,7 +41,7 @@ var (
 
 // Tagging - object tagging interface
 type Tagging struct {
-	XMLName xml.Name `xml:"http://s3.amazonaws.com/doc/2006-03-01/ Tagging"`
+	XMLName xml.Name `xml:"Tagging"`
 	TagSet  TagSet   `xml:"TagSet"`
 }