Backport: fix(amazon-bedrock): support document files in tool results

[github-actions]

This is an automated backport of #15534 to the release-v6.0 branch. FYI @aayush-kapoor
This backport has conflicts that need to be resolved manually.

git cherry-pick output

Auto-merging packages/amazon-bedrock/src/bedrock-api-types.ts
CONFLICT (content): Merge conflict in packages/amazon-bedrock/src/bedrock-api-types.ts
Auto-merging packages/amazon-bedrock/src/convert-to-bedrock-chat-messages.test.ts
Auto-merging packages/amazon-bedrock/src/convert-to-bedrock-chat-messages.ts
CONFLICT (content): Merge conflict in packages/amazon-bedrock/src/convert-to-bedrock-chat-messages.ts
error: could not apply 9d5a2992b... fix(amazon-bedrock): support document files in tool results (#15534)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"

[github-actions]

🚀 Published in:

Package	Version
@ai-sdk/amazon-bedrock	4.0.110 github npm
@ai-sdk/azure	3.0.67 github npm
@ai-sdk/openai	3.0.66 github npm