[FIX] account dashboard graph data

closes odoo/odoo#124457

Before: in the accounting journal dashboard, for bank and cash graph data the date comparison was done with a date object and a formatted date object resulting in them never being equal and duplicating data.
Now: both dates are formatted in the same way
X-original-commit: 0e2594c88dadb91acb1470dbc55b8ab37f6166c1
Signed-off-by: Quentin De Paoli <qdp@odoo.com>

addons/account/models/account_journal_dashboard.py

@@ -194,7 +194,7 @@ class account_journal(models.Model):
                 #(graph is drawn backward)
                 for val in journal_result:
                     date = val['date']
-                    if date != today.strftime(DF):  # make sure the last point in the graph is today
+                    if date.strftime(DF) != today.strftime(DF):  # make sure the last point in the graph is today
                         data[:0] = [build_graph_data(date, amount, currency)]
                     amount -= val['amount']