[#312] wc: Delete unused Iterate method

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/writecache/writecache.go

@@ -32,7 +32,6 @@ type Cache interface {
 	// Returns apistatus.ObjectNotFound if object is missing in the Cache.
 	// Returns ErrReadOnly if the Cache is currently in the read-only mode.
 	Delete(context.Context, oid.Address) error
-	Iterate(IterationPrm) error
 	Put(context.Context, common.PutPrm) (common.PutRes, error)
 	SetMode(mode.Mode) error
 	SetLogger(*logger.Logger)