Disable automatic sync schedule in sync-db.yml (#693)

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## Motivation and Context
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We have some more work to do on that so let's temporarily comment out
the scheduled cron job for syncing the database.

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## Breaking Changes
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- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

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- [ ] I have read the [MCP
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Author: rdimitrov

.github/workflows/sync-db.yml

@@ -1,9 +1,9 @@
 name: Sync Production DB to Staging (from backups)
 
 on:
-  schedule:
-    # Run daily at 2 AM UTC (during low-traffic hours)
-    - cron: '0 2 * * *'
+  # schedule:
+  #   # Run daily at 2 AM UTC (during low-traffic hours)
+  #   - cron: '0 2 * * *'
   workflow_dispatch:  # Allow manual triggering
 
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