Support for AWS SDK for Go v2 in handler.Request

Currently, the `cloudformation-cli-go-plugin` provides AWS credentials via `handler.Request.Session`, which is an AWS SDK v1 session (*session.Session from github.com/aws/aws-sdk-go). AWS SDK for Go v1 has reached [end-of-life](https://github.com/aws/aws-sdk-go/?tab=readme-ov-file#no_entry_sign-this-sdk-has-reached-end-of-support).

As the Go ecosystem migrates to AWS SDK v2 (github.com/aws/aws-sdk-go-v2), resource providers need to maintain both SDK versions or implement credential bridging workarounds to use SDK v2 clients.

**Current Workaround**
To use AWS SDK v2 services in CloudFormation resource handlers, we currently have to bridge credentials from the SDK v1 session:
```
import (
"github.com/aws-cloudformation/cloudformation-cli-go-plugin/cfn/handler"
"github.com/aws/aws-sdk-go-v2/aws"
)

func awsConfigFromHandlerRequest(req *handler.Request) aws.Config {
return aws.Config{
Region: aws.ToString(req.Session.Config.Region),
Credentials: aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
v1Creds, err := req.Session.Config.Credentials.Get()
if err != nil {
return aws.Credentials{}, err
}
return aws.Credentials{
AccessKeyID: v1Creds.AccessKeyID,
SecretAccessKey: v1Creds.SecretAccessKey,
SessionToken: v1Creds.SessionToken,
}, nil
}),
}
}
```

**Questions:**
1. Are there any plans to add native AWS SDK v2 support? Is there a timeline for this migration? AWS SDK v1 has EOL'd, and SDK v2 is the recommended path forward.
2. Is the credential bridging approach above the recommended workaround? Or is there a better pattern you'd suggest for resource providers migrating to SDK v2?