Adjust Document Embedders in core integrations to not modify Documents in place

[anakin87]

Original issue in Haystack: deepset-ai/haystack#9505

Example implementation in Haystack: deepset-ai/haystack#9693 (using dataclass.replace)

Potentially affected integrations:

• Bedrock
• Cohere
• FastEmbed
• Google GenAI
• Jina
• Nvidia
• Optimum
• Watson X

I recommend creating a PR for each integration.

[GunaPalanivel]

Hi! @sjrl @anakin87

I've created PR #2702 to fix the Bedrock integration.

✅ Updated AmazonBedrockDocumentEmbedder to use dataclasses.replace() following the same pattern as FastEmbed, Optimum, and Nvidia.
✅ Added immutability tests for both Cohere and Titan embedding paths.
✅ All tests passing.

This covers the Bedrock integration from the list. Happy to address any feedback! 🚀

[GunaPalanivel]

Hi @sjrl

I'd like to work on the remaining unchecked integrations if they're available:

• Cohere
• Google GenAI
• Jina
• Watson X

I'll follow the same dataclass.replace() pattern used in the merged PRs (FastEmbed, Optimum, Nvidia, Bedrock). Planning to create separate PRs for each integration as recommended.

Please let me know if any are already in progress to avoid duplicate work! This way, the team can focus on more complex issues while I tackle these fixes.