Code Quality: Annotate WP_HTML_Processor::next_token() as impure for PHPStan

[rejaulalomkhan]

Description

WP_HTML_Processor::next_token() advances the internal parser state, mutates element queues, and changes current depth and bookmarks as side effects. PHPStan inferred the method as pure, which caused loops in WP_Block::replace_rich_text() to be analyzed as constant and led to a false positive booleanOr.alwaysTrue error.

Annotating next_token() with @phpstan-impure accurately reflects its side-effecting behavior and allows the booleanOr.alwaysTrue baseline to be retired.

Follow-up to [63301], [63357].
Trac ticket: https://core.trac.wordpress.org/ticket/65817

---

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request outside of WordPress Core Trac.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props rejaulalomkhan, huzaifaalmesbah.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.

[huzaifaalmesbah]

Thanks for the PR, @rejaulalomkhan!

This is the same @phpstan-impure annotation as #14037 (and the older #13074), so the three overlap.

The PHPStan job is failing here because the annotation also resolves two other ignored errors in class-wp-block.php (booleanNot.alwaysTrue and deadCode.unreachable), and those baseline entries are still present. #14037 already removes them.

Would you mind closing this in favour of #14037? Happy to have your review there.

AI Review: Opus 5.5