28.3-RC1

Changes compared to: 28.2

Enhancements:

• Adds a schemamap.xml file at the site root that exposes the aggregated schema map. #23510
• Improves the performance of generating XML sitemaps by warming post, term and featured-image caches in bulk. #23348
• Adds the failing object's type and ID to the SEO data optimization error report when an indexable cannot be built. #23402
• Improves performance when running the SEO optimization by warming post and term caches in bulk. #23355

Bugfixes:

• Fixes a bug where the AI Content Planner inserted an empty paragraph block before the template blocks when a post type had a block template registered. #23401

Other:

• Adds a first-time guided tour to the bulk editor. #23509
• Sets the minimum supported WordPress version to 6.9. #23530

Non user facing:

• Update dev dependencies #23512
• Updates url sanitization to better work with UTF-8. #23053
• Shortens some file names as they can cause issues in Windows-based development environments. #23522
• Removes the "Discover Brand Insights now" and "Your first brand analysis is free!" modals that were shown after installing Yoast SEO. #23439
• Adds a CI check that reports how much a pull request changes the plugin zip size. #23471
• Adds a contributor guideline asking contributors to keep no more than 5 open pull requests at any given time. #23502
• Adds a PHP deprecation guide as a Claude Code skill and references it from the agent behaviour guidelines. #23483
• Merges the feature/performance-cache-improvements feature branch. #23517