[Feature request] Remove the functionality of `az feedback`

[jiasli]

Related command
az feedback

Is your feature request related to a problem? Please describe.

• [Feedback] Stop including error messages in the feedback body #25286 stopped including error message in az feedback's feedback body.
• {Feedback} Stop prompting az feedback #26459 stopped prompting az feedback.

az feedback is now half-deprecated.

Describe the solution you'd like
Since #26463 refined the GitHub issue template: https://github.com/Azure/azure-cli/issues/new?assignees=&labels=bug&projects=&template=Bug_report.yml, az feedback should now just open https://github.com/Azure/azure-cli/issues/new/choose without letting the user select any command. (🚀Feature request is also considered a type of feedback.)

Describe alternatives you've considered
Totally remove az feedback.

Additional context
az feedback's test relies on an old extension alias:

azure-cli/src/azure-cli/azure/cli/command_modules/feedback/tests/latest/test_feedback.py

Line 61 in 4c0f648

self._run_cmd("extension add -n alias")

This alias has packaging issues.

[yonzhan]

Thank you for opening this issue, we will look into it.