Chore: Reduce imports for a slight memory improvement (#9217)

src/documents/serialisers.py

@@ -1,10 +1,12 @@
+from __future__ import annotations
+
 import datetime
 import logging
 import math
 import re
 import zoneinfo
-from collections.abc import Iterable
 from decimal import Decimal
+from typing import TYPE_CHECKING
 
 import magic
 from celery import states
@@ -32,6 +34,7 @@ from rest_framework.fields import SerializerMethodField
 if settings.AUDIT_LOG_ENABLED:
     from auditlog.context import set_actor
 
+
 from documents import bulk_edit
 from documents.data_models import DocumentSource
 from documents.models import Correspondent
@@ -60,6 +63,9 @@ from documents.templating.utils import convert_format_str_to_template_format
 from documents.validators import uri_validator
 from documents.validators import url_validator
 
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
 logger = logging.getLogger("paperless.serializers")