Don't run scheduled jobs on forks

[rgieseke]

Scheduled jobs should only run in the main repo.
Solution from https://github.com/orgs/community/discussions/26684

Let me know if you want me to experiment with the date for testing!

This closes #708

[codecov-commenter]

Codecov Report

Merging #709 (9f4e7bc) into master (8087ca7) will not change coverage.
The diff coverage is n/a.

❗ Current head 9f4e7bc differs from pull request most recent head 0fdb129. Consider uploading reports for the commit 0fdb129 to get more accurate results

@@           Coverage Diff           @@
##           master     #709   +/-   ##
=======================================
  Coverage   79.72%   79.72%           
=======================================
  Files          61       61           
  Lines        5978     5978           
=======================================
  Hits         4766     4766           
  Misses       1212     1212           

[kdorheim]

@rgieseke thanks!

[rgieseke]

Thanks, i've synced my fork and will check next month!

[kdorheim]

Awesome! Keep us posted!

[rgieseke]

Scheduled jobs in my fork have been skipped! ✔️

[kdorheim]

Awesome!