[FIX] point of sale: check if config_currencies null

A traceback is generated if config currencies are none. This is because we are trying to access the 0 index which does not exist in a None object.

Steps to reproduce:
1. Go to studio.
2. Click on reports.
3. Search for sale details.
4. Click on sale details report.

Current Behavior:
As we click on the sales details report, a traceback pops up.

Expected Behavior:
There should be no traceback and the report editor should open smoothly if nothing wrong.

Note:
We also remove Timezone information from the start_date to match the
format of the date when it's provided by the user.
e.g. : "23/05/2024 08:25:34" instead of "23/05/2024 08:25:34 TZInfo"

OPW-3501650

closes odoo/odoo#140575

X-original-commit: c816f47eaabcb2aedce91887287f34ac8f16320a
Signed-off-by: Vlad Stroia (vlst) <vlst@odoo.com>
Signed-off-by: Robin Engels (roen) <roen@odoo.com>

addons/point_of_sale/models/report_sale_details.py

@@ -36,7 +36,7 @@ class ReportSaleDetails(models.AbstractModel):
                 # start by default today 00:00:00
                 user_tz = pytz.timezone(self.env.context.get('tz') or self.env.user.tz or 'UTC')
                 today = user_tz.localize(fields.Datetime.from_string(fields.Date.context_today(self)))
-                date_start = today.astimezone(pytz.timezone('UTC'))
+                date_start = today.astimezone(pytz.timezone('UTC')).replace(tzinfo=None)
 
             if date_stop:
                 date_stop = fields.Datetime.from_string(date_stop)