fix(amazon-bedrock): update amazon.nova-canvas-v1:0 documentation

[huanshenyi]

Background

The documentation for Amazon Bedrock's amazon.nova-canvas-v1:0 image model was outdated. It only listed us-east-1 as the available region, but the model is now available in additional regions.

Summary

Updated the region availability for the amazon.nova-canvas-v1:0 image model:

• Added eu-west-1 region
• Added ap-northeast-1 region

The model is now documented as available in: us-east-1, eu-west-1, and ap-northeast-1.

Tasks

• Tests have been added / updated (for bug fixes / features) - N/A for docs
• Documentation has been added / updated (for bug fixes / features)
• A patch changeset for relevant packages has been added (for bug fixes / features - run pnpm changeset in the project root)
• Formatting issues have been fixed (run pnpm prettier-fix in the project root)

[lgrammel]

we have switched working branches to v4/v5. can you edit the pr and set the branch to v5? also no changeset needed since its docs

[huanshenyi]

@lgrammel Thanks for the feedback!

Closing this PR in favor of #6977 which has been approved and is based on the v5 branch.

Thanks for the guidance on the branch change!