Prepare PL 3.4.0 release

[sstopfer]

This issue is to track preparation of the upcoming 3.4.0 release up until publishing, which is due August 19, 2024.

• [x] Create release/3.4.0 branch closer to the release date
• [x] Finalize scope and punt unfinished pull requests to following release
• [x] Smoke test (Friday, August 16, 2024)
• [x] Prepare the release (Monday, August 19, 2024)

[felixarntz]

@westonruter @thelovekesh Is the plan to release the Web Worker Offloading plugin as part of this release cycle? I noticed it's already in plugins.json, but to my knowledge we don't have a .org repo for it yet.

If we're not ready to publish it yet, shouldn't it be removed from plugins.json for now, to avoid triggering a release (attempt) for it with PL 3.4.0?

[westonruter]

That's right. The plan was to release it as another experimental plugin, however if we're not satisfied with the current state then we'll have to remove from plugins.json prior to doing a PL release.

[felixarntz]

Sounds good. I'd be in favor of removing it now and only adding once we know we want to and can (i.e. have a .org repo) publish it.

[westonruter]

I've filed https://github.com/WordPress/performance/issues/1455 to extend Web Worker Offloading with support for automatically offloading Google Tag Manager for at least WooCommerce and Site Kit.

[westonruter]

I've created the release/3.4.0 branch and I opened #1480 with the version bumps and readme updates. See https://github.com/WordPress/performance/pull/1480#issuecomment-2294465381 for build ZIPs for smoke testing.

[mukeshpanchal27]

Everything looks good from what I can see for the smoke test for version 3.4.0 through the release/3.4.0 branch. In this release, the picture element received some great improvements.

Enhanced Responsive Images

• Use more robust HTML Tag Processor for auto sizes injection ✅
• Remove sizes attribute when the responsive image disabled ✅
• Harden logic to add auto keyword to sizes attribute to prevent duplicate keyword ✅

Performance Lab

• Remove Server-Timing metric for the autoloaded options query time ✅
• Fix disabled options from reappearing in Site Health after external update ✅
• Improve Performance screen when external requests to WordPress.org fail ✅

Modern Image Formats

• Improve disabling checkbox for Picture Element on Media settings screen ✅
• Add missing full size image in PICTURE > SOURCE srcset ✅
• Correct the fallback image in PICTURE element ✅
• Don't wrap PICTURE element if JPEG fallback is not available ✅
• Fix setting sizes attribute on PICTURE > SOURCE elements ✅