Undo/redo doesn't work in the redesigned Custom HTML block #80541

Description

While editing code inside the custom HTML block, pressing Cmd-Z/Ctrl-Z should undo what you just did inside the text field you have selected. Currently it jumps back into the block editor and undoes whatever you last did with a block.

Step-by-step reproduction instructions

1. Add a Custom HTML block to a post.
2. Put some code into the block.
3. Press Cmd-Z (Mac OS, iPad OS) orCtrl-Z (Windows, Linux).

Screenshots, screen recording, code snippet

Environment info

• Wordpress 7.0.2
• All browsers I've tried
• Mac OS 26

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

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure