Fix console null errors in security dashboard

What does this MR do?

This MR fixes three errors (like Uncaught TypeError: project is null) on the project security dashboard which were shown in the console. It only fixes the three occurrences and not a possible underlying issue in the GraphQL/Apollo implementation (or intended feature?) returning null for the project property. I mentioned that already in the issue: #247086 (comment 422318632)

The changes should not affect any feature and only remove the error logs because the errors were not affecting features.

Relates to #247086 (closed).

Screenshots

Before	After

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