[Bug Fix] Add support for AWS_REGION override

[thomasgtaylor]

Description

When I used the AWS Bedrock LLM configuration in my article, I got a model access error because the region is hardcoded to us-west-2 in the source.

AWS_REGION is a widely-accepted environment variable for AWS credentials.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• Documentation update

How Has This Been Tested?

• Test Script (please provide)

I ran the following script:

from embedchain import App

bot = App.from_config(config_path="config.yaml")

bot.add("https://en.wikipedia.org/wiki/Ada_Lovelace")

print(bot.query("Who is Ada Lovelace?"))

with my AWS_REGION environment variable exported and an AWS profile set.

Here is the configuration:

llm:
  provider: aws_bedrock
  config:
    model: anthropic.claude-v2
    model_kwargs:
      temperature: 0.5
      top_p: 1
      top_k: 250
      max_tokens_to_sample: 200

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Made sure Checks passed

[deshraj]

Nice, thanks for adding support for this.