[FIX] pos_daily_sales_reports: traceback on printing daily sales

before this commit, on printing the daily sales report
without selecting the pos session in the wizard, it
raises traceback.

traceback:

ValueError: Not naive datetime (tzinfo is already set)
Template: point_of_sale.report_saledetails
Path: /t/t[2]/t/div/div[1]/t[3]/strong/t[1]
Node: <t t-esc="date_start" t-options="{\'widget\': \'datetime\'}"/>

after this commit, the session field will be required
in the wizard and report will get correctly printed

closes odoo/odoo#128096

X-original-commit: a77e2936790fdb179f88c3cd2de08aec801bb24c
Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>

addons/point_of_sale/wizard/pos_daily_sales_reports.py

@@ -8,7 +8,7 @@ class PosDailyReport(models.TransientModel):
     _name = 'pos.daily.sales.reports.wizard'
     _description = 'Point of Sale Daily Report'
 
-    pos_session_id = fields.Many2one('pos.session')
+    pos_session_id = fields.Many2one('pos.session', required=True)
 
     def generate_report(self):
         data = {'date_start': False, 'date_stop': False, 'config_ids': self.pos_session_id.config_id.ids, 'session_ids': self.pos_session_id.ids}