Expand performance tests setup

[swissspidy]

What this PR does:

• Run tests against Multisite, now that the local Docker environment supports it (as of r58097)
• Run tests on a single post page in addition to just the homepage
• Try to improve cache flushes / resets between iterations
• Try to improve workflow names
• Make workflow job summaries more readable by using <details>
• Collect information about object cache hits & misses, flushing cache between runs

Trac ticket: https://core.trac.wordpress.org/ticket/62725

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[swissspidy]

Collect information about object cache hits & misses

That part doesn't seem to be working yet. Looks like stats are not reset between runs.

[swissspidy]

@felixarntz @joemcgill This relates to WordPress/performance#1735

I previously opened this to test with multisite, but not sure how useful that is. Maybe we can just support it in the workflow for manual invoke but not actually run it for every commit/PR.

Second, this now tests a single post URL too, but that adds a lot of noise, as it increases the number of combinations. We might want to clean up the summary a little bit or so.

Example: https://github.com/WordPress/wordpress-develop/actions/runs/12373742576?pr=6515

Aside: The object cache stats still don't look correct and actually probably aren't useful, so I'll remove them.

[felixarntz]

@swissspidy This looks awesome! I hope we can land this soon.

Just a few questions, and some suggestions for consolidating duplicate code. Obviously we don't want to do any real refactoring as part of this, but there are a few quick and easy wins that I think are worth it.

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[felixarntz]

@swissspidy Looks great! Some suggestions, but nothing critical.

Can you open a Trac ticket for this?

[mukeshpanchal27]

In https://github.com/WordPress/wordpress-develop/actions/runs/12413679906/job/34656106232?pr=6515#step:25:50, it downloads the Firefox browser. Do we actually need that? Additionally, there are warnings during the build of Playwright. Could these warnings indicate an issue on their side? If so, it might be worth opening a ticket in their repository.

[swissspidy]

We don‘t need Firefox and in the step before we actually only install Chromium. But this download comes from wp-scripts, so this would need an enhancement ticket in Gutenberg.

Looks like these warnings are for missing audio and video codecs, nothing we‘d need for the tests.