feat: add workload identity federation between GCP and AWS

[pascallim]

Title

Allow workload identity federation between GCP and AWS

Relevant issues

Fixes #6141

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

• I have Added testing in the tests/litellm/ directory, Adding at least 1 test is a hard requirement - see details
• I have added a screenshot of my new test passing locally
• My PR passes all unit tests on (make test-unit)[https://docs.litellm.ai/docs/extras/contributing_code]
• My PR's scope is as isolated as possible, it only solves 1 specific problem

Type

🆕 New Feature
✅ Test

Changes

Add workload identity federation between GCP and AWS. It was only done for Microsoft Azure and OIDC identity providers.

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Name	Status	Preview	Comments	Updated (UTC)
litellm	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 23, 2025 0:29am

[CLAassistant]

All committers have signed the CLA.

[pascallim]

Here's some documentation:

• WIF with Microsoft Azure and OIDC identity providers: https://googleapis.dev/python/google-auth/latest/_modules/google/auth/identity_pool.html
• WIF with AWS: https://googleapis.dev/python/google-auth/latest/_modules/google/auth/aws.html

@krrishdholakia

Thank you!