Update haystack-ai requirement from >=2.9.0 to >=2.27.0

[dependabot]

Updates the requirements on haystack-ai to permit the latest version.

Release notes

Sourced from haystack-ai's releases.

v2.27.0

⭐️ Highlights

🔌 Automatic List Joining in Pipeline

When a component expects a list as input, pipelines now automatically join multiple inputs into that list (no extra components needed), even if they come in different but compatible types. This enables patterns like combining a plain query string with a list of ChatMessage objects into a single list[ChatMessage] input.

Supported conversations:

Source Types	Target Type	Behavior
T + T	list[T]	Combines multiple inputs into a list of the same type.
T + list[T]	list[T]	Merges single items and lists into a single list.
str + ChatMessage	list[str]	Converts all inputs to str and combines into a list.
str + ChatMessage	list[ChatMessage]	Converts all inputs to ChatMessage and combines into a list.

Learn more about how to simplify list joins in pipelines in 📖 Smart Pipeline Connections: Implicit List Joining

🗄️ Better Developer Experience for DocumentStores

The metadata inspection and filtering utilities (count_documents_by_filter, count_unique_metadata_by_filter, get_metadata_field_min_max, etc.) are now available in the InMemoryDocumentStore, aligning it with other document stores.

You can prototype locally in memory and easily debug, filter, and inspect the data in the document store during development, then reuse the same logic in production. See all available methods in InMemoryDocumentStore API reference.

🚀 New Features

• Added new operations to the InMemoryDocumentStore: count_documents_by_filter, count_unique_metadata_by_filter, get_metadata_fields_info, get_metadata_field_min_max, get_metadata_field_unique_values

• AzureOpenAIChatGenerator now exposes a SUPPORTED_MODELS class variable listing supported model IDs, for example gpt-5-mini and gpt-4o. To view all supported models go to the API reference or run:

  from haystack.components.generators.chat import AzureOpenAIChatGenerator
  print(AzureOpenAIChatGenerator.SUPPORTED_MODELS)

  We will add this for other model providers in their respective ChatGenerator components step by step.

• Added partial support for the image-text-to-text task in HuggingFaceLocalChatGenerator.

  This allows the use of multimodal models like Qwen 3.5 or Ministral with text-only inputs. Complete multimodal support via Hugging Face Transformers might be addressed in the future.

• Added async filter helpers to the InMemoryDocumentStore: update_by_filter_async(), count_documents_by_filter_async(), and count_unique_metadata_by_filter_async().

⚡️ Enhancement Notes

• Add async variants of metadata methods to InMemoryDocumentStore: get_metadata_fields_info_async(), get_metadata_field_min_max_async(), and get_metadata_field_unique_values_async(). These rely on the store's thread-pool executor, consistent with the existing async method pattern.
• Add _to_trace_dict method to ImageContent and FileContent dataclasses. When tracing is enabled, the large base64-encoded binary fields (base64_image and base64_data) are replaced with placeholder strings (e.g. "Base64 string (N characters)"), consistent with the behavior of ByteStream._to_trace_dict.
• Pipelines now support auto-variadic connections with type conversion. When multiple senders are connected to a single list-typed input socket, the senders no longer need to all produce the exact same type since compatible conversions are applied per edge. Supported scenarios include T + T -> list[T], T + list[T] -> list[T], str + ChatMessage -> list[str], str + ChatMessage -> list[ChatMessage], and all other str <-> ChatMessage conversion variants. This enables pipeline patterns like joining a plain query string with a list of ChatMessage objects into a single list[ChatMessage] input without any extra components.

🔒 Security Notes

... (truncated)

Commits

• 89936fa bump version to 2.27.0
• b142a82 bump version to 2.27.0-rc1
• 4686335 Fix appending None to a list in State (#10990)
• f77b09e Add _to_trace_dict for image content and file content (#10989)
• 01b11aa build(deps): bump int128/datadog-actions-metrics from 1.156.0 to 1.157.0 (#10...
• c067ef9 build(deps): bump actions/setup-go from 6.3.0 to 6.4.0 (#10983)
• bfe5aec feat: Add tests for auto joiner with auto variadic behavior (#10949)
• 93a986b docs: add TavilyWebSearch component page and external integration entry (#10954)
• aafc3a3 Sync Core Integrations API reference (azure_ai_search) on Docusaurus (#10978)
• 20487c3 docs: add AzureDocumentIntelligenceConverter documentation (#10969)
• Additional commits viewable in compare view

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