[Feature]: Add support for Bedrock API Keys

[ConnorKirk]

The Feature

Amazon Bedrock now supports API Keys to simplify the getting started experience.

Litellm can add support for this by upgrading the version of boto3 to v1.39.0 or higher. I'm not sure if other code changes are required. It might be worth also updating the docs for the Amazon Bedrock provider

Users would set an environment variable, AWS_BEARER_TOKEN_BEDROCK. boto3 detects this environment variable and uses it.

I'm happy to contribute a PR if welcome. I might need some guidance

Motivation, pitch

Make it easier for users to use Amazon Bedrock

LiteLLM is hiring a founding backend engineer, are you interested in joining us and shipping to all our users?

No

Twitter / LinkedIn details

No response

[dreamorosi]

Related #12426

[ishaan-jaff]

@ConnorKirk can you make PR for bumping boto3 on requirements.txt and pyproject ?

[0x-fang]

@ishaan-jaff can you help take a look and merge this PR to support this API key feature? #12426 We had tested it and verified it is working with API key (both env variable and pass-in api-key parameter). Thanks

[ishaan-jaff]

done and on main