mvu: fix handle missing 'auto_upgrade' column in versions table (sour…

…cegraph#52509)

We weren't returning the values when performing the fallback query,
instead returning an error regardless

## Test plan

Tested in a full run of migrator

internal/version/upgradestore/store.go

@@ -147,12 +147,11 @@ func isMissingRelation(err error) bool {
 func (s *store) GetAutoUpgrade(ctx context.Context) (version string, enabled bool, err error) {
  if err = s.db.QueryRow(ctx, sqlf.Sprintf(getAutoUpgradeQuery)).Scan(&version, &enabled); err != nil {
  var pgerr *pgconn.PgError
- if errors.As(err, &pgerr) {
- if pgerr.Code == pgerrcode.UndefinedColumn {
- if err = s.db.QueryRow(ctx, sqlf.Sprintf(getAutoUpgradeFallbackQuery)).Scan(&version); err != nil {
- return "", false, errors.Wrap(err, "failed to get frontend version from fallback")
- }
+ if errors.As(err, &pgerr) && pgerr.Code == pgerrcode.UndefinedColumn {
+ if err = s.db.QueryRow(ctx, sqlf.Sprintf(getAutoUpgradeFallbackQuery)).Scan(&version); err != nil {
+ return "", false, errors.Wrap(err, "failed to get frontend version from fallback")
  }
+ return version, enabled, nil
  }
  return "", false, errors.Wrap(err, "failed to get frontend version and auto_upgrade state")
  }