Cloud License: seat link sync even when historical data is absent

What does this MR do?

For cloud license, we want to run seat link sync even if there is no historical data on user counts. This is because seat link also serves the purpose of updating the cloud license file, which should still occur even if there is no user count data available.

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because Cloud License is a developing feature, and cloud license file itself acts as a feature flag.
• 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.

Related to #326931