[13.0][FIX][account_asset_management]: fix asset count compute to prevent expected singleton error

account_asset_management/models/account_move.py

@@ -34,7 +34,7 @@ class AccountMove(models.Model):
         for rec in self:
             assets = (
                 self.env["account.asset.line"]
-                .search([("move_id", "=", self.id)])
+                .search([("move_id", "=", rec.id)])
                 .mapped("asset_id")
             )
             rec.asset_count = len(assets)