Enhancements:
* Huge performance improvement: moves the XML News sitemap to be based on our Indexables architecture.
* Removes images from the XML News sitemap as they serve no purpose here and this further improves performance.
Other:
* Excludes attachments and non-indexed post types from the possible post types to include in the News Sitemap.
Enhancements:
* Adds Schema Article News subtypes: `ReviewNewsArticle`, `AnalysisNewsArticle`, `AskPublicNewsArticle`, `BackgroundNewsArticle`, `OpinionNewsArticle`, and `ReportageNewsArticle`.
Bugfixes:
* Fixes a bug where a duplicate News section would be shown in the Yoast sidebar in the post editor when Yoast SEO Premium is active in combination with WP 5.8.
Enhancements:
* Adds key/value pairs of all News SEO meta tags to our REST API.
* Improves the performance of the news sitemap. Props to [archon810](https://github.com/archon810).
Bugfixes:
* Fixes a bug where a database query including duplicate column names would fail on certain database systems.
Other:
* Adds a filter to override the decision to omit an item from the news sitemap. Props to [joneslloyd](https://github.com/joneslloyd).
* Sets the minimum WordPress version to 5.6.