Add support for Claude3-Opus

[watany-dev]

Issue #, if available:

ref: #368

Description of changes:

model-id's below.

https://aws.amazon.com/jp/blogs/aws/anthropics-claude-3-opus-model-on-amazon-bedrock/

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[ericzbeard]

Linter check is failing:

Run staticcheck ./...
-: # github.com/aws-cloudformation/rain/internal/cmd/build
internal/cmd/build/interactive.go:106:11: undefined: OPUS (compile)
-: # github.com/aws-cloudformation/rain/internal/cmd/build [github.com/aws-cloudformation/rain/internal/cmd/build.test]
internal/cmd/build/interactive.go:106:11: undefined: OPUS (compile)
Error: Process completed with exit code 1.

[ericzbeard]

Should be a simple fix for the linter error, then I'll merge it.

[watany-dev]

@ericzbeard
I'm sorry. I tried to fix it.