Drop luet, image extractor, drop build code and multiarch images (#20)

Co-authored-by: Mauro Morales <mauro.morales@spectrocloud.com>

pkg/action/upgrade.go

@@ -160,13 +160,6 @@ func (u *UpgradeAction) Run() (err error) {
 			umount, err = e.MountRWPartition(persistentPart)
 			if err != nil {
 				u.config.Logger.Warn("could not mount persistent partition: %s", err.Error())
-			} else {
-				// Set luet tempdir
-				tmpdir := utils.GetTempDir(&u.config.Config, "")
-				u.config.Luet.SetTempDir(tmpdir)
-				// Remove the tmpdir before unmounting
-				cleanup.Push(func() error { return u.config.Fs.RemoveAll(tmpdir) })
-				cleanup.Push(umount)
 			}
 		}
 	}