fix: replace in place dataclass mutations for pgvector #11087 (#3142)

* fix: use replace to set attr to None [11087]

* fix: avoid linting error reassigning loop vars [11087]

---------

Co-authored-by: David S. Batista <dsbatista@gmail.com>

Author: HuyDC

integrations/pgvector/tests/test_filters.py

@@ -2,6 +2,8 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+from dataclasses import replace
+
 import pytest
 from haystack.dataclasses.document import Document
 from haystack.testing.document_store import FilterDocumentsTest
@@ -42,8 +44,9 @@ def assert_documents_are_equal(self, received: list[Document], expected: list[Do
             else:
                 assert received_doc.embedding == pytest.approx(expected_doc.embedding)
 
-            received_doc.embedding, expected_doc.embedding = None, None
-            assert received_doc == expected_doc
+            received_doc_no_embedding = replace(received_doc, embedding=None)
+            expected_doc_no_embedding = replace(expected_doc, embedding=None)
+            assert received_doc_no_embedding == expected_doc_no_embedding
 
     @pytest.mark.skip(reason="NOT operator is not supported in PgvectorDocumentStore")
     def test_not_operator(self, document_store, filterable_docs): ...