fix token cache for oauth

[eric-wang-1990]

What changes are proposed in this pull request?

This PR change the OAuth token cache that when the cached oauth token cannot be refreshed, we still wanna go trigger a new OAuth login flow instead of just throwing an exception.
This help customers who use OAuth U2M, when their cached access token expire they have a way to continue rather than stuck with exception.

How is this tested?

Manual test from dbt-databricks.

ALWAYS ANSWER THIS QUESTION: Answer with "N/A" if tests are not applicable
to your PR (e.g. if the PR only modifies comments). Do not be afraid of
answering "Not tested" if the PR has not been tested. Being clear about what
has been done and not done provides important context to the reviewers.

[github-actions]

If integration tests don't run automatically, an authorized user can run them manually by following the instructions below:

Trigger:
go/deco-tests-run/sdk-py

Inputs:

• PR number: 823
• Commit SHA: 8d2337276dcf1836c6d3ea849ed32c3690f7a811

Checks will be approved automatically on success.