updated bedrock provider for the new Australian sonnet 4.5 cross region inference

[mattgillard]

This week AWS added a new cross region inference profile for sonnet 4.5 in Australia only (split across Sydney and Melbourne). This PR adds this logic to deal with it.
I tested it locally and it works fine (existing "ap" logic is unchanged just moved to the else statement).

[mattgillard]

aws bedrock list-inference-profiles --query "inferenceProfileSummaries[?contains(inferenceProfileName, 'AU')]"

[
    {
        "inferenceProfileName": "AU AU Anthropic Claude Sonnet 4.5",
        "description": "Routes requests to AU Anthropic Claude Sonnet 4.5 in ap-southeast-2 and ap-southeast-4.",
        "createdAt": "2025-10-03T21:19:52+00:00",
        "updatedAt": "2025-10-03T21:19:52+00:00",
        "inferenceProfileArn": "arn:aws:bedrock:ap-southeast-2:1234567890:inference-profile/au.anthropic.claude-sonnet-4-5-20250929-v1:0",
        "models": [
            {
                "modelArn": "arn:aws:bedrock:ap-southeast-2::foundation-model/anthropic.claude-sonnet-4-5-20250929-v1:0"
            },
            {
                "modelArn": "arn:aws:bedrock:ap-southeast-4::foundation-model/anthropic.claude-sonnet-4-5-20250929-v1:0"
            }
        ],
        "inferenceProfileId": "au.anthropic.claude-sonnet-4-5-20250929-v1:0",
        "status": "ACTIVE",
        "type": "SYSTEM_DEFINED"
    }
]

[rekram1-node]

mind resolving merge conflict?

[mattgillard]

mind resolving merge conflict?

this is done!

[mattgillard]

Conflict resolved

[rekram1-node]

thanks!