add cache warmup cronjob (#1679)

[hansmorb]

closes #1679

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.

Project coverage is 53.96%. Comparing base (743ebfe) to head (6e5e585).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/Service/Scheduler.php	0.00%	10 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #1757      +/-   ##
============================================
- Coverage     54.01%   53.96%   -0.05%     
- Complexity     2630     2631       +1     
============================================
  Files            98       98              
  Lines         12127    12137      +10     
============================================
  Hits           6550     6550              
- Misses         5577     5587      +10     

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