[FIX] l10n_br: wrong & pointless field redefinition

Fields `amount_type` on `account.tax` and `account.tax.template` are
already defined in the `account` module.
Redefining them here (with the same parameters) breaks every other
module that would have used `selection_add=` on those fields.

Actually, it is the case in `account_tax_python`, and thus, all the
localizations/customizations that depend on it were broken by this one.

(issue spotted by 11.0-nightly)

Closes #19812 #20596

addons/l10n_br/models/account.py

@@ -14,11 +14,6 @@ class AccountTaxTemplate(models.Model):
                                     help="Um percentual decimal em % entre 0-1.", default=0)
     amount_mva = fields.Float(string='MVA Percent', digits=0, required=True,
                                 help="Um percentual decimal em % entre 0-1.", default=0)
-    amount_type = fields.Selection([('group', 'Group of Taxes'),
-                                       ('fixed', 'Fixed'),
-                                       ('percent', 'Percentage of Price'),
-                                       ('division', 'Percentage of Price Tax Included')],
-                                      string='Tax Computation', required=True, default='percent')
 
 
 class AccountTax(models.Model):
@@ -31,8 +26,3 @@ class AccountTax(models.Model):
                                   help="Um percentual decimal em % entre 0-1.", default=0)
     amount_mva = fields.Float(string='MVA Percent', digits=0, required=True,
                               help="Um percentual decimal em % entre 0-1.", default=0)
-    amount_type = fields.Selection([('group', 'Group of Taxes'),
-                                     ('fixed', 'Fixed'),
-                                     ('percent', 'Percentage of Price'),
-                                     ('division', 'Percentage of Price Tax Included')],
-                                    string='Tax Computation', required=True, default='percent')