[Bug]: `dab init --auth.provider` invalid command succeeds when it should fail

### What happened?

Using `dab init --auth.provider` with a value that is not part of the allowed enum options works should cause the command to fail, however, it is succeeding and serializing the wrong value to the config file.

Command used that caused failure is `dab init --config test-config.json --auth.provider Entr --database-type mssql --auth.audience http://testing.com --auth.issuer https://testing.issuer.com`

### Version

2.0.0-rc

### What database are you using?

Azure SQL

### What hosting model are you using?

Local (including CLI)

### Which API approach are you accessing DAB through?

_No response_

### Relevant log output

```Text

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### Code of Conduct

- [x] I agree to follow this project's Code of Conduct