Make AWS Lambda role and external ID optional in create-version

[mani-j9]

create-version and update-version-compute-config hard-required --aws-lambda-assume-role-arn and --aws-lambda-assume-role-external-id whenever --aws-lambda-function-arn was set. The server already governs this via the global require_role_and_external_id setting (default true), so the client check duplicated server policy and blocked valid role-less configs — e.g. local dev against LocalStack with the setting disabled.

The updated create-version error tests assert the server-side rejection.

🤖 Generated with Claude Code

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✅ mani-j9
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