fix: Add greater than zero validation for sync_interval

[karthik-sivadas]

Description

fix: Add greater than zero validation for sync_interval

Related Issue

None

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• New Connector (Destination or Source Connector)
• Breaking change (fix or feature that would impact existing functionality)
• Styling change
• Documentation update
• Refactoring
• Chore

How Has This Been Tested?

Wrote rspec unit test

Checklist:

• Ensure a branch name is prefixed with feature, bugfix, hotfix, release, style or chore followed by / and branch name e.g feature/add-salesforce-connector
• Added unit tests for the changes made (if required)
• Have you made sure the commit messages meets the guidelines?
• Added relevant screenshots for the changes
• Have you tested the changes on local/staging?
• Added the new connector in rollout.rb
• Have you updated the version number of the gem?
• Have you ensured that your changes for new connector are documented in the docs repo or relevant documentation files?
• Have you updated the run time dependency in multiwoven-integrations.gemspec if new gems are added
• Have you made sure the code you have written follows the best practises to the best of your knowledge?

[afthabvp]

we can add validation in SyncContracts