fix: Bug with delegation credential not creating calendarSync record

[hariombalhara]

What does this PR do?

• Fixes #XXXX (GitHub issue number)
• Fixes CAL-XXXX (Linear issue number - should be visible at the bottom of the GitHub issue description)

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Summary by cubic

Fixed an issue where calendarSync records were not created when using delegation credentials during calendar sync tasks.

• Bug Fixes
  • Ensured delegationCredentialId is included and handled when creating or updating calendarSync records.
  • Added logic to create a delegation user credential in the database if needed.