fix(anthropic): Add output_config in AnthropicChatGenerator

[Keyur-S-Patel]

Related Issues

• fixes Add output_config to AnthropicChatGenerator ALLOWED_PARAMS #2894

Proposed Changes

Added support for output_config in AnthropicChatGenerator so it is no longer filtered out from generation_kwargs.

• Added "output_config" to AnthropicChatGenerator.ALLOWED_PARAMS
• Updated AnthropicChatGenerator docstring to list output_config among supported generation_kwargs
• Added unit test coverage to verify output_config is passed through to Anthropic messages.create()

How did you test it?

• Ran targeted unit tests:
  • hatch run test:unit tests/test_chat_generator.py -k "output_config or run_with_params or flattened_generation_kwargs"
  • Result: 7 passed, 50 deselected
• Ran type checks:
  • hatch run test:types
  • Result: success, no issues found
• Ran formatting:
  • hatch run fmt
  • Result: all checks passed, no formatting changes needed

Notes for the Reviewer

• This change is intentionally scoped to parameter allowlisting and test coverage.
• Existing behavior is unchanged except that output_config is now forwarded instead of being dropped with a warning.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.

[bogdankostic]

Looking good, thanks @Keyur-S-Patel