[FIX] account_statement_import: abs lines don't need partner_bank_id field

Let them use the one from account moves.

account_statement_import/models/account_bank_statement_line.py

@@ -12,10 +12,6 @@ class AccountBankStatementLine(models.Model):
     # Ensure transactions can be imported only once
     # (if the import format provides unique transaction ids)
     unique_import_id = fields.Char(string="Import ID", readonly=True, copy=False)
-    # v13 field: bank_partner_id
-    # This field was removed in v14, but it is still used in the code, cf the
-    # method reconcile() !!! So I restore the field here
-    partner_bank_id = fields.Many2one("res.partner.bank", string="Partner Bank Account")
 
     _sql_constraints = [
         (