Fix AWS LLM provider not recognized at startup

[willingWill17]

PR Description

This pull request resolves #206

Example Configuration

provider: aws
model: us.anthropic.claude-3-5-sonnet-20241022-v2:0  # Or another Bedrock-supported model
maxIterations: 50
aws:
  region: $AWS_REGION
  accessKeyId: $AWS_ACCESS_KEY_ID
  secretAccessKey: $AWS_SECRET_ACCESS_KEY
  sessionToken: $AWS_SESSION_TOKEN   # Optional, for temporary credentials

Notes

• sessionToken is optional and can be used for temporary AWS credentials.
• This change ensures better flexibility when integrating with AWS Bedrock.