stepfunctions-bedrock-sam: Update ModelId to Claude Sonnet 4.5

[kakakakakku]

Issue #, if available:
N/A

Description of changes:
Hi😀 Thanks for the useful patterns!

I noticed that Claude 2.1 can no longer be used. When actually deployed, the following error occurs:

This model version has reached the end of its life. Please refer to the AWS documentation for more details. (Service: BedrockRuntime, Status Code: 404, Request ID: 721bc128-d706-4a50-91ff-9851b0537c37) (SDK Attempt Count: 1)

Therefore, I updated the model to use Claude Sonnet 4.5 instead.

Check

$ aws stepfunctions start-sync-execution  --name "test" --state-machine-arn "arn:aws:states:us-east-1:000000000000:stateMachine:StateMachineExpressSyncToBedrock-zGv6h6rBCtpl" --input "{\"prompt\": \"Write 5 lines about how Moon was formed.\"}" --region us-east-1
{
    "executionArn": "arn:aws:states:us-east-1:000000000000:express:StateMachineExpressSyncToBedrock-zGv6h6rBCtpl:test:4a73f058-b2ea-40fe-aa56-b1bc4fcb27ea",
    "stateMachineArn": "arn:aws:states:us-east-1:000000000000:stateMachine:StateMachineExpressSyncToBedrock-zGv6h6rBCtpl",
    "name": "test",
    "startDate": "2025-11-10T00:04:51.504000+09:00",
    "stopDate": "2025-11-10T00:04:57.711000+09:00",
    "status": "SUCCEEDED",
    "input": "{\"prompt\": \"Write 5 lines about how Moon was formed.\"}",
    "inputDetails": {
        "included": true
    },
"output": "{\"Body\":{\"model\":\"claude-sonnet-4-5-20250929\",\"id\":\"msg_bdrk_014iQLvHi98ir4DN9aaqNs1P\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"# How the Moon Was Formed\\n\\n1. **Giant Impact**: About 4.5 billion years ago, a Mars-sized object called Theia collided with the early Earth in a catastrophic impact.\\n\\n2. **Debris Field**: The collision ejected massive amounts of rocky debris from both Earth and Theia into orbit around our planet.\\n\\n3. **Accretion Process**: This orbiting debris gradually clumped together through gravitational attraction over millions of years.\\n\\n4. **Moon Formation**: The accumulated material eventually coalesced to form the Moon, which initially orbited much closer to Earth than it does today.\\n\\n5. **Supporting Evidence**: This \\\"Giant Impact Hypothesis\\\" is supported by the Moon's composition being similar to Earth's mantle and its relatively small iron core.\"}],\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":18,\"cache_creation_input_tokens\":0,\"cache_read_input_tokens\":0,\"output_tokens\":173}},\"ContentType\":\"application/json\"}",
    "outputDetails": {
        "included": true
    },
    "billingDetails": {
        "billedMemoryUsedInMB": 64,
        "billedDurationInMilliseconds": 4900
    }
}

Thank you😀

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[kakakakakku]

note: Update for using Messages API.
https://docs.aws.amazon.com/bedrock/latest/userguide/model-parameters-anthropic-claude-messages-request-response.html

[kakakakakku]

note: Use inference profiles.