[Bug] Service Fabric HTTPAdapter enforcement breaks Identity SDK #963

Describe the bug

This change https://github.com/AzureAD/microsoft-authentication-library-for-python/pull/952/changes#diff-24c0727ff4626c6c535d05c13b61fa4b4a47d6fc4496ec0ceadc734191de19cbR741 breaks Azure Identity SDK's Service Fabric credential implementation because it rejects custom HTTPAdapters.

Azure Core SDK's transport mounts a custom subclass that inherits from HTTPAdapter to support Azure Storage and other high throughput services. We want to avoid importing requests in the Identity SDK just to pass a new session to MSAL.

This issue blocks the Identity SDK from adopting UAMI ARC support (Azure/azure-sdk-for-python#48708), which requires upgrading MSAL to 1.38.0.