build: remove x := x made unnecessary by the new semantics of loops in go1.22

Signed-off-by: russcoss <russcoss@outlook.com>

backend/azureblob/azureblob.go

@@ -2152,7 +2152,6 @@ func (o *Object) getMetadata() (metadata map[string]*string) {
 	}
 	metadata = make(map[string]*string, len(o.meta))
 	for k, v := range o.meta {
-		v := v
 		metadata[k] = &v
 	}
 	return metadata