Remove tab content pane padding in Dependency List

What does this MR do?

This removes an unwanted gap between the tabs and their content in the Dependency List.

This feature is currently behind the disabled-by-default feature flag dependency_list_vulnerabilities.

Before:

After:

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Performance 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