Gallery Block Gap fatal error

[Jastos]

Description

When adding a value to "Block Spacing" in a gallery block, I get:

PHP Fatal error: Uncaught TypeError: preg_match(): Argument #2 ($subject) must be of type string, array given in /wp-content/plugins/gutenberg/build/block-library/blocks/gallery.php:51

If I var_dump the value of the $gap variable, I get this value:
array(2) { ["top"]=> string(4) "30px" ["left"]=> string(4) "30px" }

If I clear out the block spacing value, or comment out the preg_match line, things work.

Step-by-step reproduction instructions

1. Install the gutenberg plugin
2. Add a gallery block
3. Add a block spacing value
4. Get an error

Screenshots, screen recording, code snippet

Environment info

• PHP 8.0.17
• Gutenberg 12.9.0
• WP 5.9.3

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

[glendaviesnz]

Thanks for reporting @Jastos - this was fixed here #39788 - and the fix should be in 13.0