When circular reference between two Schedule Blocks is set, critical exception is thrown when publishing the page.

Steps to reproduce:**
1. Create new Landing Page
2. Add two Schedule Blocks (named: S1, S2)
3. Set overflow from S1 to S2
4. Set overflow from S2 to S1
5. Wait until spinner appears

Result:
Unexpected error occurs
Error in console:

Failed to load resource: the server responded with a status of 500 (Internal Server Error)

In log:

request.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\FatalErrorException: "Error: Maximum execution time of 30 seconds exceeded" at /home/vagrant/Desktop/studiodemo/vendor/nicmart/tree/src/Node/NodeTrait.php line 226

Unknown macro: {"exception"}

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Expected behaviour:
As far as I know circular references between Schedule Blocks are not supported, so maybe an appropriate message should be displayed in the UI?