Fix `ci_project_subscriptions` plan limits

What does this MR do?

Fixes the #209303 (closed).

We do not yet have default plan, so let's not create to seed it yet.

Does this MR meet the acceptance criteria?

Conformity

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