[FIX] account_invoice_constraint_chronology: modify past invoices

Addresses the issue as commented here:

- https://github.com/OCA/account-financial-tools/issues/1206
- https://github.com/OCA/account-financial-tools/pull/1152#issuecomment-847854629

Summary of the steps to reproduce the problem:

1. Set on the invoices journal the constraint chronology.
2. Validate an invoice for this journal today.
3. Your accountant says there's an error on an invoice from yesterday.
4. Cancel it an set it to draft. You don't even need to modify anything
5. Try to post the invoice.
6. You'll get a chronology error.

In v12 this was considered but it was lost on the migration to v13:

800c02474e/account_invoice_constraint_chronology/model/account_invoice.py (L50)

800c02474e/account_invoice_constraint_chronology/model/account_invoice.py (L70-L73)

TT34624

account_invoice_constraint_chronology/model/account_move.py

@@ -94,7 +94,7 @@ class AccountMove(models.Model):
     def write(self, vals):
         if vals.get("state") != "posted":
             return super().write(vals)
-
+        previously_validated = self.filtered(lambda m: m.name and m.name != "/")
         newly_posted = self.filtered(lambda move: move.state != "posted")
         res = super().write(vals)
         for move in newly_posted & self.filtered("journal_id.check_chronology"):
@@ -104,6 +104,8 @@ class AccountMove(models.Model):
                 move._raise_sequence_ordering_conflict()
             if self.search(move._get_older_conflicting_invoices_domain(), limit=1):
                 move._raise_older_conflicting_invoices()
+            if move in previously_validated:
+                continue
             if self.search(move._get_newer_conflicting_invoices_domain(), limit=1):
                 move._raise_newer_conflicting_invoices()