[FIX] base: multi-pages and multi-records traceback

In case of a multi-record and multi-page (i.e. 2 pages per PDF) report
the assertion is triggered b/c we have 4 pages and only two records with
a PDF of 2 pages each, so the outline_page needs to be unique before
assertion.

len([0, 0, 2, 2]) != len([record_id1, record_id2])
len([0, 2]) == len([record_id1, record_id2])

closes odoo/odoo#40076

X-original-commit: 573e5777
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

odoo/addons/base/models/ir_actions_report.py

@@ -595,7 +595,8 @@ class IrActionsReport(models.Model):
                     reader = PdfFileReader(pdf_content_stream)
                     if reader.trailer['/Root'].get('/Dests'):
                         outlines_pages = sorted(
-                            [outline.getObject()[0] for outline in reader.trailer['/Root']['/Dests'].values()])
+                            set(outline.getObject()[0] for outline in reader.trailer['/Root']['/Dests'].values())
+                        )
                         assert len(outlines_pages) == len(res_ids)
                         for i, num in enumerate(outlines_pages):
                             to = outlines_pages[i + 1] if i + 1 < len(outlines_pages) else reader.numPages