Hide "Create Issue" On Vulnerability Page When Issues Are Disabled

What does this MR do?

This MR hides the "Create Issue" button on the vulnerability page if issues are disabled.

Relates to #241757 (closed)

Screenshots

Issues Enabled/Disabled?	Before	After
Enabled
Disabled

Steps to Test

1. Go to a project with vulnerabilities
2. Enable (disable) project issues
3. Click on "Security Dashboard"
4. Click on a vulnerability
5. Check that the "Create Issue" button in the related issues bar is visible (not visible)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team