Cache google sheet contents, so they're retrieved no more than once per minute

[rbren]

We are accessing a google sheet on every request to /authenticate, which can be a lot. This can get rate limited

In openhands/server/github.py, modify the logic so that the sheet's contents are cached in memory, and only updated if they're > 60s old.

[github-actions]

OpenHands started fixing the issue! You can monitor the progress here.

[github-actions]

A potential fix has been generated and a draft PR #4703 has been created. Please review the changes.

[github-actions]

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