[FIX] base: wkhtml2pdf large documents load

Step to reproduce:

    Edit documents layout in general setting to add logo and background
    select multiple documents (more than 5) e.g. Inventory> delivery slips
    print all documents.

Bug:
background and logo missing on the last documents because the pages
were printed before the browser had time to render them

Fix:
wkhtml2pdf has a default delay of 200 ms (--javascript-delay)
increasing the value will allow large document to load

opw-2951594

closes odoo/odoo#114512

X-original-commit: ac2df93eb3f08696189d010bdfa4187e02a94576
Signed-off-by: Julien Castiaux (juc) <juc@odoo.com>
Signed-off-by: Walid Hanniche (waha) <waha@odoo.com>

odoo/addons/base/models/ir_actions_report.py

@@ -296,6 +296,9 @@ class IrActionsReport(models.Model):
             if paperformat_id.disable_shrinking:
                 command_args.extend(['--disable-smart-shrinking'])
 
+        # Add extra time to allow the page to render
+        command_args.extend(['--javascript-delay', '1000'])
+
         if landscape:
             command_args.extend(['--orientation', 'landscape'])