Revert "Create a method to generate OAuth tokens (#644)"

[hectorcast-db]

Changes

This reverts commit db1f4ae9d055ff62f79374cbdfedf0e1da87cdf6.

Azure CredentialsProvider is impacted by the change: https://github.com/databricks-eng/eng-dev-ecosystem/actions/runs/9187156296/job/25264245409

Reverting to unblock the release

Tests

• [X] make test run locally
• [X] make fmt applied
• [X] relevant integration tests applied

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 91.83673% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 57.66%. Comparing base (db1f4ae) to head (4f2cd55).

Files	Patch %	Lines
databricks/sdk/credentials_provider.py	89.74%	4 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #653 +/- ## ========================================== - Coverage 57.67% 57.66% -0.02% ========================================== Files 48 48 Lines 32742 32680 -62 ========================================== - Hits 18885 18844 -41 + Misses 13857 13836 -21 ```

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