🩹 [#4320] Fix crash when rendering PDF again for cosigned submission

The PDF was including the cosign data/component for version 1 of cosign,
which is not compatible at all with v2 (see #4308), causing crashes.

Generally this doesn't matter since the PDF is generated right after
submission is received and before its cosigned, and we don't usually
need to re-generate it except during development.

src/openforms/submissions/report.py

@@ -59,6 +59,12 @@ def co_signer(self) -> str:
         if not (co_sign_data := self.submission.co_sign_data):
             return ""
 
+        # XXX this is something present in cosign v2 but not v1, which happens after the
+        # PDF is generated. Generating the PDF again after it's cosigned otherwise
+        # crashes.
+        if "cosign_date" in co_sign_data:
+            return ""
+
         representation = co_sign_data.get("representation") or ""
         identifier = co_sign_data["identifier"]
         co_sign_auth_attribute = co_sign_data["co_sign_auth_attribute"]

src/openforms/submissions/tests/test_tasks_pdf.py

@@ -559,3 +559,19 @@ def test_incomplete_cosign_data_missing_representation(self):
             ),
         )
         self.assertIn(identifier, rendered)
+
+    def test_cosign_v2_data(self):
+        report = SubmissionReportFactory.create(
+            content="",
+            submission__completed=True,
+            submission__co_sign_data={
+                "plugin": "digid",
+                "attribute": "bsn",
+                "value": "123456782",
+                "cosign_date": "2024-01-01T17:00:00Z",
+            },
+        )
+
+        html: str = report.generate_submission_report_pdf()
+
+        self.assertNotEqual(html, "")