Add support for resolving AWS region from ~/.aws/config

[jamesls]

The AnthropicBedrock client resolves the AWS region using the AWS_REGION env var or defaulting to us-east-1:

anthropic-sdk-python/src/anthropic/lib/bedrock/_client.py

Lines 119 to 121 in 9652512

	if aws_region is None:
	aws_region = os.environ.get("AWS_REGION") or "us-east-1"
	self.aws_region = aws_region

However, there are additional ways to configure region (docs). In my case, I put all my configuration in ~/.aws/config and don't set any environment variables other than AWS_PROFILE so AnthropicBedrock was defaulting to us-east-1 instead of using my configured region.

You can get botocore to resolve the region using get_config_variable on the session instance:

>>> botocore.session.get_session().get_config_variable('region')
'us-west-2

[namanvats]

Fixed it here : #539, please review and merge