Update Globus SDK and use GlobusApp objects for auth

From the #garden channel, Reid mentioned that if we use some of the more recent Globus Auth functionality, that could make it more straightforward to integrate Garden into a Claude Code like globus science agent CLI. (And this could probably clean up some of our auth logic)

https://globus-sdk-python.readthedocs.io/en/stable/authorization/globus_app/apps.html