fix(amazonq): remove Welcome Walkthrough Security Scan Feature

[laileni-aws]

Problem

In the Amazon Q Welcome Walkthrough, the "Scan your current project" button under "Check for security vulnerabilities" feature is non-functional and does not initiate any scanning process when clicked.

Steps to Reproduce

• Click the 3-dot menu (⋯) above the chat interface
• Select "Help" from the dropdown menu
• Choose "Welcome Walkthrough" option
• Navigate to "Check for security vulnerabilities" section
• Click the "Scan your current project" button

Solution

• Remove this user experience as this is a part of agentic chat experience.

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[github-actions]

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