MSAL Python 1.27.0b2

This beta release is a preview for the broker-on-Mac support. You can install it by pip install msal==1.27.0b2. Please refer to this staged API Reference Doc for how to opt into this new feature.

_{(Note to MSAL maintenance team: The tag was accidentally named "...b1", while the actual version number was "...b2". This is not a problem when we eventually do it right when shipping the stable "1.27.0" in the future.)}