Referencing local variable response before initialiazing in get_chart_csv_data error handling

[zhaorui2022]

In this line, it is trying to access response before it is initialized if auth_cookies is false. Will send a PR after creating this issue.

How to reproduce the bug

1. Run with an unauthorized user name to create an alert. When the alerts fails and tries to send a notification, it fails with error message Failed generating csv local variable 'response' referenced before assignment.

Expected results

If running with unauthorized user name, it should just fails to retrieve data.

Actual results

It fails with error message Failed generating csv local variable 'response' referenced before assignment

Screenshots

N/A

Environment

(please complete the following information):

• browser type and version: It is a backend error and is happening to all browsers
• superset version: superset version latest
• python version: python --version 3.9
• node.js version: node -v N/A
• any feature flags active: N/A

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

Additional context

Add any other context about the problem here.

[zhaorui2022]

PR: #20263

[rusackas]

@zhaorui2022 thank you for resolving this!!! If there are any outstanding issues, just say the word, and we can re-open it. Let us know if we can assist you in any further contributions to Superset.