MM-44638: Remove upgrade.go (#20309)

We remove any remaining migrations from the upgrade.go file

```release-note
NONE
```

store/retrylayer/retrylayer.go

@@ -9841,6 +9841,27 @@ func (s *RetryLayerTeamStore) GetAllTeamListing() ([]*model.Team, error) {
 
 }
 
+func (s *RetryLayerTeamStore) GetByEmptyInviteID() ([]*model.Team, error) {
+
+	tries := 0
+	for {
+		result, err := s.TeamStore.GetByEmptyInviteID()
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+		timepkg.Sleep(100 * timepkg.Millisecond)
+	}
+
+}
+
 func (s *RetryLayerTeamStore) GetByInviteId(inviteID string) (*model.Team, error) {
 
 	tries := 0