[Copilot]: Remove "Security Vulnerability" from the Issue Chooser

[kavyamsft]

Issue Description

The Issue Chooser adds "Report a security vulnerability" by default in the config.yml so adding "Security vulnerability" makes it redundant.

Expected Changes

Remove the following:

- name: Security vulnerability
    url: https://github.com/microsoft/azure-linux-dev-tools/security/policy
    about: Please report security vulnerabilities privately via the Microsoft Security Response Center (see SECURITY.md). Do NOT open a public issue.

Additional Context

No response