Limit the number of jobs that spawn for forks

[desrosj]

This limits the number of jobs that can run when a pull request is opened within a fork to a maximum of:

• 29 jobs that run in a minute or less.
• 6 jobs that take between 1 and 3 minutes.
• 18 jobs that take longer.

These jobs are spread out across 10 different workflows, and the maximum only occurs when the required run criteria for all 9 workflows is met. When only PHP files are modified, there are 28 jobs across 7 workflows with 14 taking less than 2 minutes and just 12 taking longer.

A single pull request should now take no longer than 15 minutes for the full array of jobs to complete.

Trac ticket: Core-63752.

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[github-actions]

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Props desrosj, johnbillion, jorbin.

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[github-actions]

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[johnbillion]

Looks good to me. We can always trim down further at a later date if necessary.

[aaronjorbin]

One comment that I don't think needs there and a few notes, otherwise LGTM

[aaronjorbin]

Noting that this should be 7.4instead of 7.2 if #9181 lands first

[aaronjorbin]

Suggested change

# WordPress 4.9 is the oldest version that supports PHP 7.2.

This looks like just copy paste rather than necessary based on the matrix

[aaronjorbin]

Noting that this should be 7.4instead of 7.2 if #9181 lands first

[desrosj]

I've made adjustments to the conditions to support running the full test suite for private forks that may or may not exist within the organization while still limiting forks outside of the org.

[github-actions]

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 60534
GitHub commit: d836928

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.