test(qdrant): replace in-place Document mutations with dataclasses.replace()

[Aftabbs]

Summary

partially addresses deepset-ai/haystack#11084 (partial — Qdrant).

After the in-place mutation warning was added to Document in deepset-ai/haystack#10650, four tests in QdrantSparseEmbeddingRetrieverIntegration trigger DeprecationWarning by mutating Document.sparse_embedding and Document.meta directly after construction.

Affected tests and mutations:

Test	Field mutated
test_run	doc.sparse_embedding
test_run_with_group_by	doc.sparse_embedding, doc.meta
test_run_async	doc.sparse_embedding
test_run_with_group_by_async	doc.sparse_embedding, doc.meta

Fix: replace all for-loop field assignments with dataclasses.replace() list comprehensions:

# Before
for doc in filterable_docs:
    doc.sparse_embedding = generate_sparse_embedding()

# After
filterable_docs = [
    dataclasses.replace(doc, sparse_embedding=generate_sparse_embedding()) for doc in filterable_docs
]

Test plan

• Run pytest -m "integration" integrations/qdrant/tests/test_sparse_embedding_retriever.py — should pass with zero DeprecationWarning about in-place mutations

[github-actions]

Coverage report (qdrant)

This PR does not seem to contain any modification to coverable code.

[bogdankostic]

Thanks for your PR @Aftabbs! I added a comment about reverting the changes made to CHANGELOG.md - otherwise the PR already looks good.

[bogdankostic]

Please revert the changes made here, the Changelog is generated automatically whenever we release a new version.

[anakin87]

Sorry, I already did this change in #3183

@Aftabbs I am closing your PR but thank you again!