Remove unused code path in HandleBotResponseAsync()

[glahaye]

Motivation and Context

Some dead wood is present in our code due to churn.

Description

Remove dead paths.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄