Remove custom auth for notebooks

[Xinyi Joffre (xinyi-joffre)]

Azure Quantum notebooks is being deprecated on October 15. Custom DefaultAzureCredential is no longer needed after this date.

Behavior changes:

• Interactive auth is no longer part of the upstream DefaultAzureCredential. If user wants to use interactive auth, they need to explicitly pass in a default azure credential that has the flag set to use interactive auth.
• Tenant discovery is no longer part of the upstream DefaultAzureCredential. If using guest user with need to explicitly select a tenant, either use azure cli and ensure azure cli is already logged into right tenant, or pass in a credential with flags for the right tenant id.

[Xinyi Joffre (xinyi-joffre)]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Xinyi Joffre (xinyi-joffre)]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Yousif Almulla (almullay)]

DefaultAzureCredential calls are replaced consistently. Looks good.