Add migrations to remove corrupted advisories

Signed-off-by: Tushar Goel <tushar.goel.dav@gmail.com>

vulnerabilities/migrations/0037_auto_20230120_1204.py

@@ -0,0 +1,29 @@
+from django.db import migrations
+from packageurl import PackageURL
+
+from vulnerabilities.severity_systems import SCORING_SYSTEMS
+
+class Migration(migrations.Migration):
+
+    def remove_advisories(apps, schema_editor):
+        Advisory = apps.get_model("vulnerabilities", "Advisory")
+        deletables = []
+        for advisory in Advisory.objects.iterator(chunk_size=1000):
+            print(advisory.pk)
+            for ref in advisory.references:
+                if not ref["url"]:
+                    deletables.append(advisory.pk)
+                    break
+                for sev in ref["severities"]:
+                    if sev["system"] not in SCORING_SYSTEMS:
+                        deletables.append(advisory.pk)
+                        break
+        Advisory.objects.filter(pk__in=deletables).delete()            
+
+    dependencies = [
+        ("vulnerabilities", "0036_alter_package_package_url_and_more"),
+    ]
+
+    operations = [
+        migrations.RunPython(remove_advisories, reverse_code=migrations.RunPython.noop),
+    ]