Description

I've updated my WP to 5.9. Now there is new junk added before </body>, some SVG's and Style's.
This does not make sense, because I'm not using FSE and have disabled duotone and gradients.

Step-by-step reproduction instructions

1. View html code of a page rendered with 5.8
2. View html code of the same page rendered with 5.9
3. In 1.) there are no SVG and Styles before closing body but in 2.)

Screenshots, screen recording, code snippet

No response

Environment info

• Wordpress 5.9 with its Gutenberg
• Own non-FSE theme
• theme.json with dutotone:[], and customDuotone: false

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes