fix: dedupe command FieldError with only("id") and select_related (#14350)

Using findings.only("id") while select_related traversal was still
active on the queryset caused a FieldError. Clear both select_related
and prefetch_related before calling only("id") so the async dispatch
path works regardless of how the queryset was constructed.

Also switch --dedupe_batch_mode from store_true to BooleanOptionalAction
so the flag can be explicitly disabled with --no-dedupe_batch_mode.

Co-authored-by: Ross E Esposito <ross@defectdojo.com>

Author: valentijnscholten

dojo/management/commands/dedupe.py

@@ -1,3 +1,4 @@
+import argparse
 import logging
 
 import pghistory
@@ -53,7 +54,7 @@ def add_arguments(self, parser):
         parser.add_argument("--dedupe_sync", action="store_true", help="Run dedupe in the foreground, default false")
         parser.add_argument(
             "--dedupe_batch_mode",
-            action="store_true",
+            action=argparse.BooleanOptionalAction,
             default=True,
             help="Deduplicate in batches (similar to import), works with both sync and async modes (default: True)",
         )
@@ -130,12 +131,13 @@ def _run_dedupe(self, *, restrict_to_parsers, hash_code_only, dedupe_only, dedup
                 elif dedupe_sync:
                     mass_model_updater(Finding, findings, do_dedupe_finding_task_internal, fields=None, order="desc", page_size=100, log_prefix="deduplicating ")
                 else:
-                    # async tasks only need the id
+                    # async tasks only need the id; clear select/prefetch_related to avoid
+                    # FieldError when combining only("id") with select_related traversal
                     from dojo.celery_dispatch import dojo_dispatch_task  # noqa: PLC0415 circular import
 
                     mass_model_updater(
                         Finding,
-                        findings.only("id"),
+                        findings.select_related(None).prefetch_related(None).only("id"),
                         lambda f: dojo_dispatch_task(do_dedupe_finding_task, f.id),
                         fields=None,
                         order="desc",