Activate on-demand scans nav item when editing a site profile

• Related issue: #239385 (closed)

What does this MR do?

This ensures that the On-demand Scans nav item is activated when editing a DAST Site Profile.

Screenshots

Before	After

How to test this?

• Navigate to the DAST profiles library /:namespace/:project/-/on_demand_scans/profiles/.
• Create a site profile.
• Edit the site profile.

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