Python: [Feature]: Default to `ad_token_provider` when providing Azure credential

[cecheta]

Description

When using an Azure client and providing a credential, the client generates and uses a token. For long-lasting clients, the token generated may expire while the client is still being used. Could the credential instead be used to create an ad_token_provider?

Instead of:

agent-framework/python/packages/core/agent_framework/azure/_shared.py

Line 199 in 474b313

ad_token = get_entra_auth_token(credential, token_endpoint)

do

# from azure.identity import get_bearer_token_provider

ad_token_provider = get_bearer_token_provider(credential, token_endpoint)

This way, the token provider will ensure that a new token is regenerated if it is expired.

Code Sample

Language/SDK

Python