I'm encountering an issue when using `redshift_connector` with Okta-based authentication inside my organisation's SageMaker environment.

In `OktaCredentialsProvider.handle_saml_assertion` I receive an error [okta_credentials_provider.py#L158](https://github.com/aws/amazon-redshift-python-driver/blob/fd81061c4dfee9ed3001be039f6b1826d8366302/redshift_connector/plugin/okta_credentials_provider.py#L158) despite receiving a 200 OK and a response of length > 2k.

Upon investigating the logs it seems to be down to a browser or Javascript issue? I've tried on both SageMaker Studio Code Editor and SageMaker Notebook instances and get the same issue.

It's also strange that `OktaCredentialsProvider.okta_authentication` works perfectly and I'm able to retrieve the `okta_session_token`, but the later step fails.

The same identical code works perfectly on my local machine.

I've attached the relevant part of the response below:

```
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Commencez dans redshift_connector/plugin/okta_credentials_provider.py, au niveau de handle_saml_assertion, en particulier à la ligne 158, et comparez le traitement de la réponse entre une machine locale et SageMaker. Confirmez si la réponse de SageMaker peut être traitée de manière compatible et documentez un test reproductible ou le comportement attendu pour la correction.

Rédigé par le modèle d'indexation à partir du texte de l'issue.