Generate with Copilot generates a PR title but no description.

[robert-smith-maersk]

• Extension version: v0.82.1
• VSCode Version: 1.87
• OS: Mac OS
• Repository Clone Configuration (single repository/fork of an upstream repository): single repository
• Github Product (Github.com/Github Enterprise version x.x.x): Github.com

Steps to Reproduce:

1. Click button to create new PR.
2. Click the sparkle button in the PR title box ('Generate with Copilot')

[alexr00]

The description provided by Copilot probably failed one of the checks we do to make sure it's reasonable, in which case we don't show it.