[FIX] account: include 'quantity' in '_compute_all_tax' dependencies

Summary
-------
This commit addresses an issue where fixed taxes were not calculated
correctly when applied to a line with a price of 0.

Steps to reproduce
------------------
1. Create a fixed tax with an amount of 5.
2. Create an invoice with a line having zero price and apply the fixed
   tax.
3. Save the invoice. You should have a total of 5.
4. Change the quantity of the invoice line, to something like 2.
5. Save the invoice.

We expect the total to be 10, but we get 5.

opw-3212536

closes odoo/odoo#134762

X-original-commit: 2aafff6a36bd40719de9447a7ab9bf05274ff5d2
Signed-off-by: William André (wan) <wan@odoo.com>
Signed-off-by: Séna Serge Nshimiyimana (sesn) <sesn@odoo.com>

addons/account/models/account_move_line.py

@@ -909,7 +909,7 @@ class AccountMoveLine(models.Model):
             else:
                 line.tax_key = frozendict({'id': line.id})
 
-    @api.depends('tax_ids', 'currency_id', 'partner_id', 'analytic_distribution', 'balance', 'partner_id', 'move_id.partner_id', 'price_unit')
+    @api.depends('tax_ids', 'currency_id', 'partner_id', 'analytic_distribution', 'balance', 'partner_id', 'move_id.partner_id', 'price_unit', 'quantity')
     def _compute_all_tax(self):
         for line in self:
             sign = line.move_id.direction_sign

addons/account/tests/test_invoice_taxes.py

@@ -715,3 +715,22 @@ class TestInvoiceTaxes(AccountTestInvoicingCommon):
         self.assertRecordValues(invoice.line_ids.filtered(lambda l: l.account_id.account_type == 'asset_receivable'), [{
             'balance': 686.54,
         }])
+
+    def test_fixed_tax_with_zero_price(self):
+        fixed_tax = self.env['account.tax'].create({
+            'name': 'Test 5 fixed',
+            'amount_type': 'fixed',
+            'amount': 5,
+        })
+        invoice = self._create_invoice([
+            (0, fixed_tax),
+        ])
+        self.assertRecordValues(invoice.line_ids.filtered('tax_line_id'), [{
+            'credit': 5.0,
+            'debit': 0,
+        }])
+        invoice.invoice_line_ids.quantity = 2
+        self.assertRecordValues(invoice.line_ids.filtered('tax_line_id'), [{
+            'credit': 10.0,
+            'debit': 0,
+        }])